Married in HS, advice please

So I've been dating my SO for a while and we have been talking about marriage and want to get married in our senior year, 2018. To be more specific, soon after graduation. He says he wants to get married then and have the celebration/reception later. Can we do that? What's a good way? We live in Texas, if marriage laws have anything to do with this. He is foreign and all of his friends and other family live back in Japan. What's a good way we can include them too?

Also

If you came on to this post to judge me and tell me how to live my life please fuck off. I am trying to get advice.

Thank you in advance💕