It was so easy to make friends during my undergrad because I lived in the dorms. But I lost half of them due to a messy situation with my ex girlfriend, and the other half doesn't live in town anymore.
Now I'm 22, working on my Master's, and I feel like I have no one.
I hope I'm no longer banned. (Hurray, I'm no longer banned from this place)
I'm looking at @StalinIsMaiWaifu as I was failing with 1, 3 and 4, although that was 20 years ago.
It's not about "talking to people". I'm not good at that, so that didn't work for me.
The biggest win for me was joining the anime/game/book (all-rolled-into-one) club,
as it was the ideal social setting for me.
The people I ended up making friends with were those that just joined,
because those don't have friends yet and once they do, they no longer look for new ones, just like you would.
You should look for those people in particular.
Those are the three best advices I could give you.