First of all, welcome aboard!
Secondly, you did great for what you paid by the looks of the pics.
Once you get through the new member probationary period of 2 months and 10 posts you should be able to score many of the
parts you need like the headlight and tail light right here in the classifieds section of this forum.
I am not sure who makes that pipe. I can identify a few of the ATC pipes but not all. And yours I do not know what it is, but it looks like it might be a nice one beside the dent.
I would at least run a quick compression test to give you a rough idea of the condition of the top end. A stock engine should be around 190psi if it is fresh. Also, a compression test can be helpful in determining what type of fuel to run, whether it requires race fuel or pump fuel.
I don't ride dunes, so I am not sure of the nuance things duners typically do to make their rides do what they want in the big sand.
As to fuel and oil. That is a very well covered and debated topic. After much reading and researching for myself, I have settled on running castor based oil (Maxima 927) at a ratio of 32:1. Do your own searching and researching and make an informed decision for your own reasons based on your particular situation. Every R owner isn't in the same exact situation
Congrats on an awesome score! Around where I live you would be lucky to find an air cooled R in somewhat rough shape for what you paid for that '85!
