my boyfriend and I want to marry but he is not born in the U.S.

My boyfriend is from El Salvador and my family is Mexican but I am born in the U.S. We have been talking about getting married lately, we are pretty young we will be turning 20 this year but we know that God is the one who has united us and we've been together for two years now. However we are not sure how to deal with his immigration status, he came here illegally and I would really love for him to get his papers and be documented so we can visit his family together! I asked him to ask my parents for my hand in marriage but were scared they will think he wants to marry me for his immigration status because we want a civil marriage first and then by the church. We don't know how to handle the situation so if any of you have any advice or know how this whole situation would work out legally we could really use it! Thank you in advance! ❤️️