Nobody have answer your questions. No; you dont need a license but it is recomended you join AMA(kind of a lic), for $60 you get insurance and you need to be in the AMA to join a club.

Second, yes you can fly anywhere, but avoid people and houses, you will get in a lot of trouble if you hit, or God forbids, injure a person or a car.
The clubs have flying sites, with runways. Yes a empty road can be a runway, but again you have to watch for obstacles, trees (they attract planes and eat them), poles, curbs, mailboxes, people, dogs (cats are ok), etc. That is another advantage of a club.

Some hobby shops have used planes they sell at consigment for other people. My first trainer was a Sig LT40 that I bought used at my LHS for $150.

Welcome to the addiction, it is a one way road, once you are in there is no way out.