I figured it out. You go to interpret footage for each imported clip, and change the pixels to “widescreen dv/ntsc?, and it makes it look like a normal widescreen with the leterbox matte.
In the future, when I film in 4:3, I have to edit in 4:3, cause if you edit in widescreen with 4:3 footage, the stupid black bars happen.
Does anyone know if any quality will be lost? I really hope not.