Hi, welcome to OSM! I just briefly checked the buildings you drew -- they look pretty good, but a quick tip is that once you 1. draw each one 2. tag it as a building, then with the building selected you can 3. press 'q' (or right-click select the squaring tool) to make the corners 90 degrees (if they're close already). It can make the resulting building look tidier. Thanks again for the edits!