Hi, Rochichi-If you run out of balls during a round they will be replaced with the free ones. You can buy balls during a round and they will be usable in that round but they have to be the exact same ball, right down to the color.
Rochichi98: Now if I purchase a new club say a putter but, I don't like it can I switch back to my old putter whenever I want?
Yes but you can't do it during a round. Whatever you start a round with you have to finish with, even if you save the game and come back later.