I have found someone I want to marry and wants to marry me. How should I go about telling my parents?

1- Pray two rak’as everyday and then gift it to Imam Mahdi (a), then ask him to intercede for you so Allah facilitates it. Just like the Fajr prayer. The Niyya is to pray a recommended prayer to Allah. Then when you finish the prayer, say O Allah I gift this prayer to Imam Mahdi (a). Then ask for you Hajat.

2- Recite this Du’a daily:

https://www.duas.org/Amn.htm

3- Talk to your mother first. Inform her that you are ready for marriage. Show her that you understand the responsibilities of marriage, and how you plan to manage your marital life, work (and studies if you are still studying). Parents need to feel confident that their children understand the responsibilities of marriage and that they are up to them. Parents also need to be confident that you are not making this decision because you are in love and acting emotionally. So you have to demonstrate to them that this a rational decision you are making, not because you are influenced by feelings.

Once she is convinced then speak to your father. It they end up refusing, have a respected elder in the family talk to your father.