I did the same thing a few years ago when I got my MC license. I bought a non-running bike, had limited repair knowledge, and with the help of the experts on the forum and lots of internet research got it running. It will be fun.
Now, on to your questions. I would suggest you get a Clymers or download the service manual (search for thread for that). Then do/check everything that is on the maintenance schedule, regardless of mileage. Make sure you check the tires for dry rot. With the limited mileage they might appear good, but your life rides on those.
Take the tank off and clean it. I used drywall screws and acetone. Count out a number of screws and put them in the tank and shake the heck out of it, then shake some more. You will definitely want to take out the fuel sending unit and petcock so you don't damage them. When you are done, make sure you get out the same number of screws that you put in. I didn't have to worry about the sending unit and petcock in my tank. Maybe someone here has a better option for your tank.
Take the carb
apart, you will want to know how to thoroughly clean it, especially if you have rust in the tank. If it has been sitting it is probably clogged with old gas. You can buy an Ultra Sonic cleaner at Harbor Freight. It is not the best, but will get the job done. I have cleaned many carbs with it. After that use air to blow it all out. Change the fuel filter after you clean the tank, and buy two, because you will probably need to change it again soon.
I hope this gets you started. Take your time and do it right now. I know it is difficult, but trust me, do it right the first time so you don't end up on the side of the road, or having to take it apart to do it again.
One last thing, pictures will really help when asking questions.