Hello, you have generally identified buildings in the imagery and mapped them quite accurately. They'd be even more accurate if you map the footprint slightly smaller than the roof you see. You created some invalid shared nodes between buildings and residential areas: hold alt to prevent your cursor from snapping to existing data. If you want to map a round feature, then right click it and circularise it, or use the short cut o. 

The following are more comprehensive comments regarding the previous points;

Please do not connect the corners of buildings to other buildings or features such as highways or residential areas. In the iD Editor, hold down the `Alt` key to prevent your cursor from snapping to existing data and accidentally creating shared(grey) nodes. This [video about connected nodes](https://youtu.be/ltn1VOiq5_0) has more information and a guide.

After tracing and tagging features which are likely square or round, please remember to square their corners (q), or circularise them (o), because it is almost impossible and time consuming to draw shapes so percisely by hand. Buildings with metal or pitched roofs tend to have square corners; round buildings are identifiable by the distinctive cresent shaped shadow they cast. Unless the building is clearly a different shape then it's best to assume that it should be rounded or its corners should be squared. In the iD Editor, you can right click for access to editing functions. Since roofs tend to overhang walls trace the initial shape slightly smaller to allow a buffer for any change in size that may occur. In JOSM use the [buildingstools plugin](https://wiki.openstreetmap.org/wiki/JOSM/Plugins/BuildingsTools). In ID you must draw the shape accurately enough else shapes will not completely square. This [video about squaring features in ID](https://youtu.be/Xs5wX592E1o) has more information and a demo.

Thank you for your contribution. If you want to experience the OSM community or to get timely feedback from other mappers; I recommend that you attend a mapathon. You can find events here https://osmcal.org/