The Dhammapada is a popular and famous summary (here in the West at least). It more or less opens with "non-hatred" (aka "loving-kindness") and has other "ethical" chapters. It's better for your purpose to read the verse[s] only, not the stories which accompany each verse.
I think the "most concrete" exposition of Christian ethics is the Great Commandment (in two parts) -- the Sermon on the Mount is ... longer, and maybe more fanciful. Anyway there's one verse in the Dhamapada which (for what it's worth) seems to me very close to the second part of that, i.e.,
- All tremble at violence; all fear death. Putting oneself in the place of another, one should not kill nor cause another to kill.
(which may seem to conflict with the anatta doctrine; "but there you go" as is said colloquially).
There's one sutta (which I remember as, "the sutta of the four directions") which contains a great deal of mundane practical advice for lay people1
There are the four "brahmaviharas", which these articles describe e.g. as follows ...
These four attitudes are said to be excellent or sublime because they are the right or ideal way of conduct towards living beings (sattesu samma patipatti). They provide, in fact, the answer to all situations arising from social contact. They are the great removers of tension, the great peace-makers in social conflict, and the great healers of wounds suffered in the struggle of existence. They level social barriers, build harmonious communities, awaken slumbering magnanimity long forgotten, revive joy and hope long abandoned, and promote human brotherhood against the forces of egotism.
The Brahma-viharas are incompatible with a hating state of mind ...
The primary ethical 'laws' are the five precepts.
There's maybe a gradual training for laypeople -- virtues includes "harmlessness" and "giving (dana)".
There are three (sometimes two) root poisons.
There's a list of hindrances (a bit analogous to what some Christian theology calls "sins") -- but there are more less detailed lists of these (and from different schools), see also especially fetters for example.
It's hard to summarise in one place2 -- I'd be remiss not to add that it says a good friend is important (to some extent all-important) -- but then again there's "seclusion" (and so on).
1 There's at least one whole paperback of advice to laypeople, based on i.e. summarising suttas like this one -- almost all of which is about the "virtue" (perhaps aka "ethics") part of the threefold training -- e.g. if you count advice like this as part of "ethics".
2 possibly because Why isn't there a Buddhist Bible? to which the accepted answer doesn't even mention Mahayana.