Welcome! I love Big Bolts and can't wait to see pictures of your truck.
There have been numerous threads posted in the various forums about starting an engine that has sat for a while. A search of the forums should turn up plenty of good advice there. As you suggested, the fuel tank would definitely be on that list. Again, a lot of info on that topic already in the forums. Plus, others will chime in with even more good advice.
Best of luck with your project and keep us posted on your progress.