Doing Bodywork on my own car need some assistance. Please

DA the old paint with 180. Do your body work over 80 grit. You can shape the filler with 8o then finish it with one 80. You can also do your filler over epoxy.

The epoxy usually needs to be topped with 2K with in 72hrs, The tech sheet will tell you how long you have. After that you have to scuff it to top coat it.

For the 2K I do my blocking with 180, usually 2 rounds to make sure its straight. So 180, then re-prime. Then I go 180 again but leave enough material to go over it with 220 if I can. If not re-prime and block with 220. Primer should fill the 220 scratches.

Then re-prime and wet sand with 400, then 600. Remember to use a guide coat each time to sand.