electrical question

[1969Chev]

I have a 1969 Chevy CST/20. I recently have started to get it ready for a new paint job. I removed the side marker lenses and the park lights (i have a 72 grill/bumper). I had to move my truck so threw it back together really quick and i have a taillight out, but it comes on when i hit the breaks, i have a park light out, and two of my side markers dont work. Do any of you know what this could be? Ive tried to look around and see what i can do, but whatever i do, doesnt seem to help.