Dear user RiMaDu, please try to make your buildings rectangular (there's a hotkey in the ID editor for that, and the people from whom you received your Mapathon training should have explained that to you). Also, please supply a human readable changeset comment; the OSM community doesn't know what CIBPH is and doesn't care that you are "Team Tricia" - we'd prefer to read something like "traced buildings near PLACENAME" or or so! 

You don't have to make an individual upload for every building, it is totally fine to draw 20 of them and upload in one go.