Here are the Planets with the trainers on them. Click on the Planet name to see a list of trainers

Earth (3 trainers)

Namek (2 trainers)

Old Vegeta (1 trainer)

New Vegeta (2 trainers)

Yardrat (1 trainer)

Self Training

You can learn Split Form (2 days), Tri Form (5 days), Solar Flare (6 days), and Dragon Fist (8 days)