can I ask how old you are? that might impact my suggestion but the best social events come from things you enjoy.
music is a big one for me. there’s a lot of 16-18+ “underground bands” that play every other month in my city so I look out for flyers if I want to go. most of these music people have an after party so you just leverage your way into a conversation by an easy compliment (be genuine) and ask a follow up. you’ll get the hint quickly if they wanna talk and from there boom you’ve got a fun friend who you can go to more of these events to. join a club. there’s a mutual interest so a higher likelihood of a connection. do sports, maybe go to a gym more often. striking up a conversation is terrifying at first but it gets easier with practice.
If ya don’t want to branch out like that, what hurt you from asking your friends if you can go to the functions they’re at? Start trying to gain more mutual friends so that group activities would be more interesting. more people = more ideas = more things to do. Throw your own party and ask your friends to invite their mutual friends. there’s probably even apps for friends you could use to meet up with people close to you! I promise the possibilities are endless