Tattoo advice ma'ams and sirs?

First of all, I'm still pretty young, so there is absolutely nothing set in stone. But I'm thinking of getting a tattoo when I'm older. More specifically, a very small infinity symbol on the side of my heel done in white ink. It wouldn't have any special design or anything like that, just a very simple tattoo. But I want some questions answered from people first. 1) does anything weird happen with white ink? like decently strange discoloration or anything? 2) pain on a scale of 1-10? 3) how much do you think a tattoo like this would cost? 4) any other tips/things i may have forgot to ask would be simply beautiful! thank you very much! :)