how do i make it?

i googled it and it said something about electrolysis but it didnt explain how to do electroysis.

electrolysis is when you run an electrical current through water, you have to have a negative wire at one end and a positive wire at the other end, and have electricity running through it.

so what would be in the water in order to make potassium perchlorate

A potassium salt with a lower oxidation state. You can made perchlorates from chlorates, which can be made from chlorides.

If you had actually read what Google told you you'd already know exactly what you need to do. There's no way for us to make it any simpler for you because it's "too hard" for your little 13 year old brain. If you keep asking the question the answer isn't going to change to become any easier.

Also, Bad Ideas is the wrong forum for chemistry/pyrotech/explosives questions.