You are starting to observe things with more clarity, noting that there is nama and rupa (mind and body) and also noting an awareness of both. In other words, you are experiencing awareness (knowing, consciousness) as its own object, distinct from the sensations it accompanies. This is good.
Continue sharpening your mindfulness. Maintain your continuous mindfulness longer, and observe more detail about whatever arises. Observe them the very moment they arise, and watch them change, and disappear.
Maintain your calmness and concentration - these are 2 factors that are helping you along the path. (There are 7 factors of enlightenment - mindfulness, investigation, energy, joy, tranquility, concentration, and Equanimity)
If things progress, observe the 5 aggregates. This may open further depths of knowledge and experience.
The oneness you refer to is a concept, one which you're now desiring. During practice, there may be times when you experience oneness as a feeling, and sense that you are everything and everything is you. Don't strive to seek it out, or build up strong expectations or desire for it. It will occur naturally as long as your mindfulness, concentration, equanimity, etc. continue to develop.
Oneness is simply another experience to observe with mindfulness and Equanimity. It occurs with increasing strength as you let go more and more of your concept of self, and know that everything you sense is in your mind. That sound you hear isn't out there, it's within your own mind. When you experience the whole the world within, then you feel a oneness.