As I question if I have bitten off more than I can chew, I settle into just one object and try to bring it along a bit. Then move on to another. Piece by piece, I am learning a good deal about modeling in color. Just what color is that shadow? How does that color change as the form turns through shadow into local color into highlight? Try to notice all the gradations on the way.
And as I gain a bit of satisfaction as form develops, only to sigh as I see errors or more detail, it's all a dance of learning and I love it.