shy and scared of communication and relationships! Please help!

I'm 18 and have never been in a relationship before but a boy asked me out twice and I just feel totally out of my comfort zone. Well to start - I met him at a party couple of months ago and I didn't really speak to him until I was drunk, and then only recently he asked me out on Messenger saying if I wanted to go to movie but I kind of freaked out so I friendzoned him saying maybe we'll go with my friend (his cousin). He asked me out again and I said I want to get to know him as a friend, now he's coming round to his cousin's (my best friend's) house next week expecting to see me there.

I don't know what to do! I've been getting myself in a state thinking about all that could go wrong, I don't want to blank him and ignore him if I see him but I feel that's what I do. And maybe he only likes me because he thinks I'm confident but I was drunk when I spoke to him so it doesn't really count and I think I told him personal stuff plus I've only seen him once. I'm used to keeping to myself, never really socialising with people other than my friends. What do I even say if he asks me stuff? Iike I don't think I even have anything to say about myself. Or anything interesting... After 'hi' I'll probably just cry internally.

I know I have low-self asteem but it's not for any silly reason, just generally don't think I'm appealing to anyone so kinda wanna be alone but at the same time don't want to be alone forever. My best friend and sister are like 'go for it' but I really can't, I can't even message him because I wouldn't know what to say and that's not even in person.

What do I do I know I don't know him but he seems really nice

I read your post twice and realise you are probably tense and worried about seeing/meeting up with the guy, which is perfectly natural.

At 18, you are young and have your whole life ahead of you - if he goes round to your Cousin's place next week then it may be an opportunity for you to say hi to him or chat.

Perhaps it may be a good way forward for you to not put yourself under any pressure.

You sound like a very caring, mindful and insightful person - all of which are very positive.

Whatever choices you make for you future, please continue to be mindful and considered.

Good luck and I wish you well - be good to yourself and take care.