Consider how many people you want to attend first. This will decide your next options. If you want to just have you and your partner or you two and a couple friends/family, your options are limitless. You don't have to have a big space and catering and all that extra planning isn't necessary. In my state you can have an ordained minister marry you. Many can get this and if one of your friends has this, may marry you for free. That means only having to buy the marriage license. For me and my partner, we will likely be married by a friend who is ordained in a forest away from trails and with a beautiful view. I live in the PNW so I am hoping he arrives when we have some good weather.
I have been told there are eloping businesses that can have a place ready for you and your partner and a few guests to have a ceremony and take pictures.
Depending on how many people you want to invite, you might be able to reserve a suitable spot with a few months notice. You have 6 months from the time of the medical exam to travel to the United States. That means you could technically try to time things just right to make a reservation after the interview and after a time when it is assured everyone will be in the US.
Consider what you can plan and take care of now. Decide how many guests and what you can and are willing to pay for like food, venue, photography, etc. Get the attire picked out as that can be done now
Wishing you all the best in your planning and next steps 💜