I'm a male, age 29. I noticed recording myself I sound better using an upper register or head voice I guess. 🤔 with this course, which recordings should I be singing? All? 

All singers should be using chest voice, head voice, and a "mix" of the two (in the middle). You can use this video to find your over all range https://www.youtube.com/watch?v=ArVkyaMQiSI and ultimately use whichever range feels like the most comfortable fit! It sounds like you'd be most comfortable with either tenor or alto range, but feel free to try them both out.