A teacher can be misguided in some aspect like view but be a good meditator to an extent.
Example is Devadatta, he tried to kill the Buddha but was a good meditator by common folk standard and certainly near perfected samadhi faculty.
Thai Forest has within it people who are able to do some sort of meditation worth learning, best chance i think is within circles that practiced asubha.
Id caution tho as i expect those developing primarily samatha to be prone to wrong views and overestimation with magnificent attainments, Devadatta could fly even.
However you as yogi now should be most concerned with learning the texts to an extent that you can distinguish what is rightly spoken from what is wrong, doing this alone will make even trees sotapannas let alone a fine person like you.
"Why, Mahaanaama, if these great sal trees could distinguish what is well spoken from what is ill spoken, I would proclaim these great sal trees to be Stream-Winners... bound for enlightenment https://www.accesstoinsight.org/tipitaka/sn/sn55/sn55.024.wlsh.html
As to teachers on the internet, if you can find a person who will teach you the instruction as it was taught in the early Buddhist texts then you are lucky.
Most teachers online will teach little to none of it and often teach a modified popularization complete with all the traditional baggage that the lineage in which they were trained accumulated over the years.
Insight meditation is not something one does, first one learns the texts, then one thinks about them a lot and try to develop at least modicum understanding meanwhile also developing gains from meditation to facilitate that understanding's development.
Ideal for most people now would be to learn the texts and go find just a place to meditate in peace with requisites and a suitable chill community that practices heightened sila & doesn't annoy one.
During the first 500 years monks memorized thousands Buddha's discourses over 40 years of teaching where he answered most FAQ and monks just taught it on. I think people underestimate how much has been answered directly by the teacher and how there is absolutely no need for a popularization, modification or a simplification of any kind.
With this in mind my advice is to find any teacher you can online and ask to be taught only the very basics and common mistakes that people do go from there on your own.
As a beginner having affiliation with a teacher figure or a person close to the holy life is incredibly beneficial, it won't carry you over the finish line but it might give you the pep talk to drag your ass over it.
Just taking the basics is the safe play as it simplifies everything and doesn't risk becoming fixated in wrong view.
As a meditator the worst thing is to get attainments, visions, see one's mind become immensely powerful and removed from worldly things and think one is an arahant or something... This is so difficult to recover from because the attainments are rare and meditators generally secluded & content.
As a beginner meditator one should therefore avoid learning the texts backwards starting from modern interpretations, commentary and never getting to the teacher's message and to avoid blindly accepting the Dhamma as Dhamma without comparing it to teacher's message even if the teacher can fly or if the meditator himself starts to fly. I mean one should certainly accept that the training did this but one might question the theory behind it and a person's interpretation so one doesn't go wrong like Angulimalla.
As to general "meditation" development, it starts with a lot of discipline and willingness to let one's best judgement guide your decisions, calming down and contemplating the dhamma somehow or doing little to no thinking.
It's kind of difficult to go wrong if the discipline is good and one entertains a wholesome theme, good things will happen and at some point one is not a beginnger anymore and should really learn more texts to progress further.
I'll comment on some famous teachers that i have approached;
- Yuttadhammo Bhikkhu, teaches solid cookie cutter meditation for beginners that goes well into rupa jhana but has little focus on cultivating lights & visions and encourages working in the 1st jhana a lot due to the noting.
I think this method is very simple and effective in it's simplest form, is good to get started and is not restricted as to possible attainment if one doesn't get caught up wrong views.
- Leigh Brasington, teaches another solid cookie cutter meditation for beginners that goes well into first jhana and beyond, here the biggest difference to the former is that this is done without excessive thought which is rather tedious and there is little to no noting of breathing let alone mindstates, factors of enlightenment and themes. This is a very simple relax and just observe kind of training aimed at producing lights & visions.
Both of these approaches are similar, the immediate difference being is that one focuses at breath at the nose and another at the belly/diaphragm and then the amount of noting is considered tedious more so by Leigh and is at times discouraged, that is it.
I personally think one should train sometimes closer to what Leigh teaches and sometimes closer to what monk teaches and neither of the two advocate much formal contemplation of themes like gratitude, compassion, impermanence, danger, death & etc which are necessary to incline the mind to the Deathless and stilling quickly.
For this reason i think Leigh's method is better but it has relative cons in this regard as well because the monk teaches more so to observe the themes of one's mind if not doing something about it at least taking note is helpful for future reference if one was deciding to develop countering themes because if your training is focused on work in the 1st jhana with thinking and be discouraged from non-thinking, then you sure as hell better incline it to go into cessation or lights & visions or one will be stuck neither attaining signs nor signless meditation.
If one only does Brasington method, it will get one to lights & visions and from there if one contemplates properly mind can quickly go to signless release or formless releases inb4 signless release, the difference is that perception of space has no shape or color by which it is described and there fore these are formless but there is attention given to a sign, a feeling & perception of boundless space and it is therefore not a signless release.
I am sure there are many other teachers but from what i've seen in monks and lay teachers, most will be closer to Leigh Brasington lest one is in Northern Thailand or Burmese Mahasi circles.
I think Pa Auk is a bit more versatile type of approach with many themes for development but to me it is a bit narrow sighted and rediculously rigid and tries to conform to as much commentary as possible which i think is a mistake.
Imo at some point before 5th century commentary seems to have obviously turned into people who have the opportunity to read a little or hear something with half an ear and then commentary freely as long as people in immediate community allowed them to do it, kind of like online Buddhist discourse but think palm leaves and no electricity. Basically i think as memorizers became rare the commentary tradition became kind of a ffa and political.
Imagine being a monk in 5th century, one part of a sutta is at your monastery another is elsewhere maybe 30 miles away, a third part is in reconstruction and a fourth part you don't know where is at within 100 miles. Whilst your monastery is only blessed with a modest amount of precious palm leaf your primary job is maintaining those and whatnot by storing & making backups. Think it is easy to learn the Dhamma?