Does anyone exactly know how to make good griptape or any ideas? I would really like to start making grip tape because it would be fun and cool to use. Please help.

Why would you need to make grip tape ? Rolls of skateboard griptape are very cheap and effective.
Are you talking about a rubber foam tape ? If so, I would expect you'd need some pretty pricey equipment to make foam tape.

just a heads up no one will tell you how to make grip tape for fingerboards , you have to figure it out on your own

This is the "humans will never figure out how their brain actually functions" of fingerboarding. Nobody really knows how foam tape is made because most, if not all of it is made in China or in a factory somewhere.

Most people in fingerboarding outsource their tape as far as I know. They don't make tape like they do a deck or even wheels.