Birth control

Ok so I’m thinking of going on the depo shot and I just had a few question and want some opinions on it.

1st off I’m 17 about to be 18 in just a couple months

2nd do you have to have a parent with you to get the shot if your under 18?

3rd does it effect your period schedule?

And 4th if you’re on the depo shot can the guy ejaculate inside you?

Also if you’re on the depo shot feel free to express how it is for you and the difference it makes