/ic/ - Artwork/Critique

hey /beg/
i'm a guy trying to take drawing seriously (dropped it at a younger age because i didn't see it as a viable hobby). im now into bara and wanna try and see if i can get into drawing it so i DO have a "milestone" in mind (plain cumbrain isn't my goal)
i tried taking up drawing again already but didn't understand the importance of concepts such as form, perspective and using shapes but now i'm trying again with these in mind, practicing boxes and other shapes and trying to apply them into construction.
what i can see here is i don't have confidence with my lines and erase too much. anything else you guys can point me towards? i have no idea what level i'm at because i have no recent memory of my older drawings
pic is two figure references from quickposes, right one is like that because the model had clothes on