Can I keep my dog indoors till I can afford a license?

Well you can, but pretty soon your home will stink. If you can't afford a license, then I suggest you can't afford a dog with everything that goes with owning one.

Your puppy can be outside in your enclosed back yard, which is where he should be until he's had all his vaccination shots in any case. I seriously doubt anybody would report you in any case unless your dog escapes and you are found to be keeping him without one. You need to start as you mean to go on with house-training or you'll have one confused puppy.

No. The dog needs to be exercised.

No! Not unless you train them to go to the bathroom in a litter box or something. My uncle Trained his dog to go in a kiddy pool with newspaper in side of it. They just keep it in their spare room and the first time she went potty in it they gave her treat and they keep on giving her treats untill she did it without treats! It works really good for him maybe it will work for you untill you can afford a dog license:) I hope this helped!