First time *actually* dating a girl?

So I’ve only ever dated guys- 3 in total... none of them ended well. I’ve been talking to this awesome lady for a while now and it looks like we might start dating (I want to presume but that’s how it’s feeling). I’m a little nervous about anything sexual... I’m ace, and she knows I am, but so did all of my previous partners and it became a problem. Any tips? Advice? 😅