Is it ok if I have a 16 gb iPhone 6s?

I have only like 20 apps and the rest are pictures and I stream vids. It's that ok?

What do you mean "Ok"?
If it works for you, fine.

It is not okay if you haven't purchased it yet and still have a chance to by 32gb, that seems like you wanting to use like 17 too many apps for that amount of memory

Of course it's ok