Sex 😊

So me and my boyfriend have been dating for a while. We are both 17 and he's had a lot of sex in the past and I'm a virgin. I know that we will have sex in the future. I'm not scared or nervous, I'm ready for it. But before all this he said that he wants to go down on me. Since I've never done sexual things with anyone else before I'm afraid that I might smell down there or taste really bad. I'll be the first girl that he's ever gone down on. Any tips on how to prepare for that so that I'm not gross down there?