When it comes to acquaintances I think everyone feels like they're putting in more effort than they are getting out of it. But once two people are friends that changes. To me, that change to a friend is when two people want to hang out on their own from time to time and it hopefully stops being a challenge or an effort. (If you're neurotic it can still be an effort, like freaking out the house isn't clean when people are coming over.)

I kinda get it also. I’m not tall and handsome.

This has less to do with friendships than you think. It does have a bit to do with acquaintances, but not as much as you'd think. And not to toot my own horn but I'm a natural light blonde, not a super model, but my mother did modelling, so not far off. On the other side of the grass, people who interact with me come in two types: 1) they want to fuck me or 2) they want to take advantage of me. My looks keeps everyone else away, leaving me having to make the effort to go out of my way to get to know people well enough to possibly one day become a friend. It's way more difficult if you're not looking for a romantic relationship when the only people who want to talk aren't interested in a normal friendship.

But what is there to do....? How do you get good at activities when you don’t have friends to do it with?

Me, I go to the movies (I bring a blanket. Fuck what anyone thinks.), and watch movies and tv at home. I go hiking quite a bit, thankfully because I live by a bunch of trails. I go for walks to 7-11 sometimes. I do go out and eat alone, but not often. (And there is, of course, Reddit. XD)

I find the anxiety of doing something alone is from it being unfamiliar. I remembered being anxious going out to eat dinner alone, but thought it was funny because for a year at a job I'd go out and do lunch alone many days of the week and never had any anxiety over it. It's almost like I needed a justification to do a thing, which was silly.

I’m 27, I need something more to life. Any input welcome.

I go to meetups and conventions based around hobbies I have. Oh and I have hobbies, and I like learning new things. I'm pretty introverted myself and enjoy doing my own thing, though it wasn't obvious to me how much I enjoyed doing my own thing until I learned to turn acquaintances into friends and enjoy it but realized how time consuming it is. Friendship is not bad if you like doing dinner with a friend once a week or so. That's what I do.

Also, if there are good restaurants on your way from work to home, that's my excuse for hanging out. Though a friend of mine likes watching anime with me quite a bit. ymmv