If you are living in your home county, your other half is a U.S. citizen, and both of you decide you should come to the United States to live together as husband and wife, a fiancé(e) visa can be a solution. When you obtain the fiancé(e) visa, you have to enter into the United States and marry your fiancé(e) within 90 days. And then you can start the process to have your green card.
One important thing for you to know is that you can get your green card only through the marriage to your fiancé(e). And not all marriages have happy endings. And then things can get complicated if you are not careful.
If you have problems in your marriage or if your marriage ends in a divorce, you may still get your green card. But you may need help with the process. If you need assistance, get in touch with an immigration lawyer who can help you.