It takes two days to find each Dragon Ball, in which the first one, you can do nothing else, and in the second one you can find the dragon ball and treat it as a normal day. You can only randomly find 5 of the balls; Guru and Frieza have the other two. Anyone with at least 2 dragon balls can wish for something, and those with more than 5 can wish twice.
Guru: To get the one from Guru, you must be a good person, and not have fought any Nameks, even the evil ones.
To get the Ball from Frieza, you must fight him in his final form. Anyone can join the fight with him, but only those with dragon balls can get the dragon ball from him and I will decide that. He also has Frieza's Space Ship that can hold 5 people, and goes to the person that has the least amount of dragonballs. The first three forms can be fought by anybody on Namek that treats him like NPC. You only get the stat boost from him in these first three battles, so you cannot get money or items from him.
Form1: Power Level - 1000 MP - 1500
Form2: Power Level - 2250 MP - 2000
Form3: Power Level - 3500 MP - 2500
Form4: Power Level - 5000 MP - 3500
Moves - Punch, Kick, Upper Cut, Jump Kick, Frieza Ball, Laser Eyes, Death Ball, Destructo Disk, Triple Attack, Rocket Punch
Items - Namek Dragon ball, Frieza's Space Ship, and $1500 to whoever fights him