When do I submit documents for Common App?

I’m using common app for the first time and I’m confused about when I’m supposed to send/submit documents such as a college report, mid-term report, transcripts, and etc. Do I send them one by one as I complete them or do I send all of the documents together at once after completing them?

YOU don’t send them. You add your guidance counselor to Common App and they do all that. When you submit your common app, all that stuff will submit along with it.