Courthouse Wedding and Family Reception

Hello! I am hoping that someone can help me with this. I will start by saying that I am terrible at being a bride-to-be and I am an absolute nervous wreck. This is about to be a long read.
😂 Originally my fiancé and I were planning on a courthouse wedding and then a small “thing” with just our families, but we quickly realized we do want to celebrate with our friends and family but still not have a full-blown “thing.”

We recently started referring to it as a reception and seriously looking at venues and I am starting to panic. We have planned to send out invites saying we were married in a small ceremony and now want to celebrate with our loved ones. But this has started to present some issues that I had surrounding having a wedding in the first place. I have pretty bad social anxiety (medicated, in therapy), and have absolutely no interest in doing the big entrance, emotional dances, toasts, and all of that stuff that happens at receptions. I really don’t like to be the center of attention, so this party is honestly just us celebrating with friends and family informally. I had envisioned a buffet, drinks if people want them, and places to sit and hang out.
Everyone just keeps telling me I can do whatever I want, but I don’t know how to do that.
My question is: how do you go about planning a “reception” that isn’t really a reception in a place big enough for friends and family? More like someone’s graduation party or open house would be. (We would do it at a house but we just wouldn’t be able to fit everyone).
I can’t forgo the whole thing because my fiancé really wants to do this and it means a lot to my family. I’d like to thin out the guest list but he hasn’t asked for much and I’d hate to tell him the people he wants there can’t come. Any suggestions would be greatly appreciated.
Thank you!
(tl;dr: don’t want a formal reception due to my issues but still want to celebrate with many friends and family in a celebration more like an open house or grad party)