You can collect unfound Dragonballs with a radar in a week, by becoming the guardian, or by searching for a month. Each of these only gives you one dragonballs. If a team gets the Earth dragonballs, they get 3 total wishes, Namek on a team gives 2. Vegeta still gives 1.
Or, you can fight someone for one of their's.
Earth Dragonballs give you 1 weak wish. Namek Dragonballs give you 1 medium wish. Vegeta Dragonballs give you 1 strong wish.
Earth Dragonballs SEPHIROTH ELITE IS IN POSSESSION
Namek Dragonballs
Vegeta (Black Star) Dragonballs