Welcome to OSM!

You spotted buildings in the imagery but generally mapped their footprints oversized. 

When mapping buildings, please trace the shape accurately. Accurate building footpritns aid population estimates and prevent issues like data overlaps. Zoom in so that you can see the outline of the building and mark the corners carefully. Exclude shadows and yards when tracing the footprint.  Keep in mind that you are looking at the roofs of buildings, but mapping their footprints. Depending on how the scene is lit, pitched roofs may have light and dark sections that belong to one building. Generally pitched roofs overhang the walls of a building, so a footprint slightly smaller than the roof is accurate. You can scale selected features in ID with shift+(-/+), or JOSM with ctrl.+alt+Lclick & drag.  Take care to make contributions that others can build upon.

On several ocations you created inappropriately shared nodes between the footprints you added and existing feeatures. Hold alt to prevent the generation of shared nodes.

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/