Restoration Commence.

The rust doesn't look too bad if it is only on the outside. Worst is when your have rust-thrus from the inside, usually first behind the front and rear wheels. I don't see that. It looks like the sun degraded the paint on horizontal surfaces and then they rusted. I would use a wire brush on a drill to remove it on the outside (safety glasses!), especially on the C-pillar, to see how pitted it is. If lucky, it will clean up to smooth metal fairly quick.

Once you get to bare metal, you can spray rattle-can primer. I suggest a "self-etching" primer. But don't paint over rust pits - they will return. If you can't brush out or sand the pits away, look at rust-converting primers to seal it in the pits. If you can't put in the effort yet to get it ready for primer, a neat product I just started using is Rustoleum Rust Inhibiter. It is a clear petroleum product in a spray can, I guess between WD-40 and the cosmoline grease they coat military rifles with. The advantage is you can remove it easily when ready to do a full job. I spray it on nuts and bolts after I wire-brush the rust, but don't want to paint and wait days to install (and lose them).