I'm intimidated that hes so....cool I feel like I don't deserve him?

so I'm 15 dating this 18 and I've learned about his past that he was engaged and then he wasn't and I've seen pictures of his ex's and they'er very pretty and have probably had experience with drugs and sex and kissing and parties and I haven't been to any, while I've never dated and hes had sex and I haven't and I'm even wondering why he even likes me, and I know its not because of sex, and I just don't know what to do because I feel like I'm dating a greek god.