Felt awkward at cousins wedding?

Very typical

Many, many people feel awkward at family gatherings. It's normal especially if you're not close to these people.

You and your brother isolated yourselves at your table and didn't mingle. Interaction is a two way street, so it might have been nice if some of your cousins approached you, but they didn't. You could also have accompanied your Mother as she made her hellos.

Sounds like you try to avoid people all the time. If you had been braver and approached a cousin and said Hi, then you would have interacted and perhaps gained a bit of social experience. Sitting safely with your brother (and he with you) didn't actually give you much of a feel-good feeling did it.

The reason it feels awkward is due to not socializing with your cousins and others there. Key thing about weddings is the chance to talk to other people, either relatives or not and meet new people and re-establish and catch up with family. Some family you won't see in your life except at weddings or funerals.

I fail to see what the problem is here.

You made polite conversation. Nobody was looking at you to magically turn into Bob Hope or something, where you'd be telling jokes and keeping everything enthralled with your wonderful conversation. Nobody is THAT focused on you (or anyone else).

Either learn to open up a bit more, or be a polite introvert. Nobody really cares either way. But skipping out on family events simply because you don't like being an awkward teenager (which happens to EVERYONE) is just rude and immature. Don't be That Guy who rudely avoids people.

If you want to get better at something then avoiding it won't help ... you have to practice.

If you prefer not to be a social butterfly, fine, but just be polite. You don't have to carry every conversation but don't hide in a corner or play on your phone either. It's practice for adulthood, so get used to it.

I think what you want to remember is that the older you get, the more the focus will be on friends as well as family. When I was 18, I enjoyed weddings, but since my extended family was mostly local, I ended up seeing the same people I saw all the time. It was ok, but nothing special.

However, all this changed after I went away to college and graduated. We all scattered and so did my sibs and I. There were still family weddings, of course, but I started getting invited to friends weddings. Then 3-4 years go by and everything changed. I'd see college friends I hadn't seen, and relatives I hadn't seen since high school. This is when it started becoming fun.

You could of gotten up out your chair and mingled. Nothing was stopping you from chatting with your cousins. You are adults. You shouldn’t need to be close friends or have a bond with people in order to talk to them for one evening.

This would of been an opportunity to get to know your cousins instead of isolating yourselves by not leavening your seats at the table.

Your FELT awkward because you were BEING awkward. Hosts don't invite you to parties for the sake of watching you gobble and guzzle and hide yourself among the people you already know. Hosts invite you to parties in the hope that you will be a social asset, in the hope that you will do your part to make the party more pleasant. Family event or not, if you don't know people at a gathering then it's your responsibility to become acquainted. Stop being a social klutz and start introducing yourself to people. It's not hard to say "Hi, I'm Elijah" and stick your hand out.

maybe you should invite them to do stuff with you so you can bond with them more