Spraying primer over paint

[Slammed70]

Well, I FINALLY quit my dead end job that Ive hated since day one.

So now I got the time to work on my truck and make it decent to drive again.

Hopefully tomarrow my roll pan will be in and I can throw it at my truck.

This is my question, my truck is isnt really painted. It got like....one coat of some semi-glossy white primer stuff on it. Im not sure what it is, but Im pretty damned sure its not paint. But when I go to lay down the primer over the new pan and the welds, should I take my handy scuff pad and take the shiny off where Im gonna blend the primer into the paint stuff?

Ive never painted before, so any tips on this would be helpful. I dont plan on painting my truck for another year or so. So naturally this has to last a while, and I would like for it to look fairly decent....and not like Earl Shyys went over it with a rattle can.

Thanks,
Mitch