what's the best type of birth control?

I'm 14 years old, I'm sexually active but not wanting to have actual sex I just want to make sure I'm fully safe when doing other stuff as I get worried really easily. I can get it for free on the NHS as I'm in the U.K. and I think all types of birth control is available for me. I would just like to know what people recommend as I heard the pill isn't as affective at preventing pregnancy as some other methods?