How do I prepare to have protected sex?

Jennifer
tips to prepare to have sex?
tips to avoid pregnancy?
I know, probably a stupid question. Lol
Please no harsh comments! :) 
But my boyfriend and I are 16, and I'm the one who decided I was ready to have sex with him.
I told him my only scare was that the first time i have sex with him, I'll get pregnant.
and I really don't want that to happen obviously lol.
any tips would be so helpful!