One of the dumbest stigmas in the world is that if you don't have anyone to hang out with, then you shouldn't go out solo because it's lame. Why on earth is this a thing? Who decided that you need others around in order to enjoy an outing?
As a society, we tend to think that acceptance from your peers equates to your self-worth. It's why the beauty industry for men and women exist (though it's been a bit more focused on looking good for yourself these days). Thus, if someone is out and about in public by themselves, the stereotype would suggest that they have no one to spend time with and should be pitied and/or ridiculed.
What if there's a super cool event going on tonight that you desperately want to go to, but none of your friends can make it due to prior commitments? You're just supposed to stay home and sadly watch recap videos of it the next day? I don't think so! You pick your butt up, march it to the place, and have the time of your life!
Growing up shy, I am well acquainted with feeling awkward standing against a wall because you came alone or bothersome because you don't want to walk up to random people that you kind of know and ask them if you can tag along. If that's the case, start out with going to smaller places and work your way up.
I recently took myself out to dinner at one of my favorite restaurants in Eugene after covering an event for my reporting class. Since it was a last minute decision, there wasn't time to hit up all my friends and see if anyone wanted to meet me there within the next ten minutes, so I decided to just go alone. I thought I would feel weird sitting there by myself, and it was admittedly a little different, but I ended up enjoying a peaceful dinner while working on the beginning of my project, listening to music, and browsing social media.
Now I'm not saying that you should completely isolate yourself. Spending time with friends and/or family can be a lot of fun and it's incredibly healthy for your mental health. I'm also not saying that you should bash everyone who dares to go out with people while you stay home thinking how much better you are than them just because you enjoy different amounts of social time.
All I'm saying here, my friend, is that you shouldn't be afraid of spending time with yourself. You might end up having more fun than you were expecting.