Nervous for my first date... any tips?

Autumn • 17 years old and I have been in a relationship for almost 3 years 💜
Okay so me and my boyfriend r going on our first date ever to celebrate our 1y 6m anniversary. It's a restaurant In town. Nothing romantic considering 100% of the places r fast food, Chinese, or pizza places. So I'm assuming casual clothing?? I don't want to over do it but I want to look nice too, ya know? I don't have any dresses, I'm basically a jeans and tee shirt kind of girl. But I'm still nervous. Any tips? am I over reacting?