This is why you register somewhere.
Somewhere. Anywhere. It doesn’t have to be at the finest department store in town. You can register at Target. At Bed, Bath, and Beyond. As others here have pointed out (isn’t this a great community? Nobody here knows everything, but between us all, we sure do!), you can register for power tools (if only they’d had that back when I got married! I’m soooooo fucking jealous!!) or for honeymoon travel.
Mrs.F. and I went the traditional route and registered for fine china (very unlike us!) and we’re glad we did. We don’t use it that often, but we love it when we do, and we’d have never bought it on our own.
Guests: weddings/receptions differ so much from one to another. I’ve been to small ones with a dozen or so people. I’ve also been to the ‘sit-down dinner for 200’ type receptions.
We had about 75 people at ours. And they were all people that at least one of us knew well: family and either very close or fairly close friends. I could pull out the photos today, eleven years later, and tell you stuff about every person who was there that day - and I’m more of an introvert than an extrovert. These were the people who were our friends and loved ones, the people who we really cared about and who cared about us. It was like a family reunion of our true, spiritual family.
However the numbers work out, invite those people. Unless you really do need to see a shrink about your shyness, you should be OK amidst such a group.
But if you are so shy that you’d feel overwhelmed in that sort of group, do a small wedding with immediate family and just a few of your closest friends. Because you really do have to invite your wedding guests to the reception, no matter how informal. (And go with as informal as you like. It’s your day.)
Then have a big, informal picnic-style reception a month or so after you get back from the honeymoon, that all your friends and relatives can come to, and you can show up at in blue jeans if you want.