Hmm, if they're not giving you feedback that's useful, best to ignore it. I suppose you could begin to look into the foundations of light theory, or perspective, or even composition, but those are tools that you build up over time and unless you are focusing on them specifically they don't just slot into place in two weeks.

If you're following Bob Ross, I think that's a pleasure in and of itself. His tutorials are almost spiritual more than mundane! Don't focus on what is 'right', just focus on what makes you feel good. What communicates peace and sentiments of calm? Blues and horizontal lines and sunny days all boil these ideas down to their most basic pieces. I think you could keep going with exploring even those three things if you're enjoying practicing.

Hope you're not getting too bogged down with the rest of RL. Don't stop practicing!