You have to start thinking about buying paint supplies. Get the panels, body, and chassis in Primer so they do not rust. Body you want to go over on 80 grit and then 220 grit with a DA or Orbital Sander. Air powered or modern electric 120vac palm orbital sander. All sorts of methologies. Epoxy primer regarded as best. 2 stage with a hardening agent and thinner to spray at different air temps. Single stage is cheep stuff but used for decades. Still works does not always last long. Afterwards metal work repair and straightening and making the panel perfect. Ideally all metal work done before hand. It's just you 1 guy. It's a Big project with lots of Blems. Flash rust will begin soon on bare steel. Get them in 2k primer.