I would for sure do paint first then interior.
When you pull the windshield and rear window out you are going to have rust that needs to be repaired. Water standing in the corners and trapped by the trim. With interior in it takes way longer and you will regret.
It is way easier to paint a car with all the windows, fenders off. Do not have to mask as much.
You need to look at cowl also to see if you have holes which you probably will have. Right and left ends if rust stains inside and rusty front floors then the cowl is leaking.
Also the roof rails will need attention, also rust and you will have to remove interior trim to do that.
You will need new rubber seal for the rear window. New roof rail rubber, 3-M strip windshield seal for front.
To get the front out you need a windshield cutter you can get at Harbor freight. Keep it wet with WD-40 will go through the goo better. Have to be careful or you will crack the glass.
In back you can just cut the old rubber seal and get out easier.
Be careful with the trim front and rear repo is not good. Need special tool to release the clips and pry up the trim with plastic trim tool.