Need friend advice :(

I'm 21 years old and can really only say that I have 2 friends. One is my boyfriend, who is also my best friend, and the other is a girl I used to work with and meet up with every few months (and we don't message frequently.) I would love to make some more friends and have close female friends! I am a very friendly person and get along well with work colleagues etc but just can't seem to build solid friendships! Plus the only place I meet people is at work so I feel a bit limited. I'm not friends with anyone from school anymore and I've had lots of friendships just fade away due to lack of communication. I just need some advice on how to make friends as I feel that I've forgotten how to!