If you're talking about that marker below your avatar where it says *blank* trainer, then that changes as you post more and more. I'm a Rainbow Trainer because I've posted over 80 times. As for when you make it a custom saying like I see on some users, I don't know how to do that.
Hi, no problem, my pleasure.
I'm Sophie, pleased to meet you.
Do you need help on this website?
I can make people banners, goo and see my Shop for stuff I can make. If you want me to make you a banner etc, just leave a message there.