If you're a virgin you're going to be a little nervous about sex whatever size you are. Take your time, don't be in a rush to get rid of your virginity, in itself virginity is neither a good or a bad thing. Wait till you're with someone you're at ease with and your nervousness won't be so bad, as for your size, whether it's vaginal sex or anal sex you'd be surprised what both of these orifices can handle, the vagina is designed to be fairly tough, you can happily pound away and it will take it - childbirth is far tougher on it than any cock in the universe would be no matter what some 'I tore her up' guys might like to think. She'll tell you if you're going to deep for her comfort but don't worry that you're going to do damage, that's highly unlikely. As for anal I'd say that's not really something a virgin should be trying with someone who isn't experienced at it, it needs more care than vaginal intercourse, you can't use too much lube, you can't take it too quickly but being blunt, a rectum is more or less an open ended tube and can take any length.