The good news is I managed to draw some transistors in magic. The bad news is I drew an m3 mim capacitor and a. it has DRC errors b. I can't delete it because it complains

You selected one or more subcells that aren't children
    of the edit cell.  Only those in the edit cell were
    deleted.

(1) Use the "i" key to make sure you are selecting a cell rather than something inside of it. (2) Many cells will have DRC errors when by themselves, such as minimum metal area errors, that will have to be resolved in the parent cell.