There are some very decent bits of advice in here, but also a shitload of absolute, terminally online, borderline mentally ill BS.
If you can actually discern which is which, then there is hope for you.
>pro tip: any form of self victimization is not good aadvice

Also:
>language classes
That tip is fucking golden if your social circle is male dominated and/or small. I had to take one as I needed the credit, otherwise I would have never taken that shit. But they are full of all kinds of girls, including the elusive homebodies and shy types, but also very social (and hot) exchange students that just try to find some connection. It's also easy mode. It's a language class, you can not not talk to anyone, eventually you will be grouped up for practice and it's piss easy to keep talking from that. You are after that awkward initiation phase due to the class and now who you vibe with in your group. Just keep talking and see where it goes/if it goes anywhere.
Biggest caveat though, if you're past 30-35 this is not really an option anymore. You've aged out of it to work for that, simple as.
But for anyone under that it's the best place to be to meet some new people organically.

>fmale friends
Semi related to above. Always memed as cuck-like or beta. BS. Who knows the most women? Other women.
Why do you think Chad always has female friends? Easy access to fresh prospects and to garnish his social events to attract more Chads that bring their female friends. See how that works?

>confidence
Why do you not get what confidence is?
It's being knowledgable about your passions, without sperging out. It's excitement to share cool stuff without gaf what others think. It's just talking to people because they are just people, not to say the right shit to unlock a gf like a cheatcode.
Also sometimes it's walking into a place like you own it, or at least feel right at home there. Nothing else.
Caveat: Works best when young as teenage girls eat that shit up.