Welcome to OSM! You identified buildings in imagery, tagged them appropriately and generally interpreted the overall shapes of buildings well, however the imagery allows them to be mapped more accurately. Please watch the following two short videos about mapping with the ID editor;

https://youtu.be/Xs5wX592E1o 

https://youtu.be/ltn1VOiq5_0

Please keep this feedback in mind when contributing in future. 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/