How to make friends?

So I’m awful at making friends in person. I know it sounds lame, but I feel I guess lonely sometimes because I don’t have many. I have my SO, who is my best friend, 2 female friends and one good male friend. That might sound like “enough”, but even the friends I have I’m not really super close to. I guess I’m just bad because I’m typically shy and don’t usually know what to say to people. It’s easy to talk about stuff to people I already know because I know their interests and stuff, but my mind is always blank with strangers. I guess I just want to be able to make really good life long friends you know? I’m horrible at talking to girls especially even though I am one; I find it easier to make friends with guys. In the long run though that can kinda become a problem because first it would be weird to do one on one stuff with them (my SO would hate it) and usually guys I’m friends with end up liking me as “more than a friend”. I want some girlfriends…..I just don’t know where to start. I’m in my senior year at university and literally have no good friends on campus aside from my SO. Anyone I know is just a random acquaintance that I might occasionally just say hi to. All the friends I have I always met through a common acquaintance, not on my own.