How do i initiate a first kiss?

I'm meeting my gf afterschool tomorrow and I rly want to kiss her but I know I will probably fuck it up and since I have such high anxiety already I just want it to be good.

AHHHH I'm overreacting so much it's not even a big deal.

I just don't know how to "set the mood" or something. So like do I just put my hands around her neck or something or do I sit down next to her and go from there??

Idk I'm over thinking it and I just need to do it.

(but any advise would be greatly appreciated)