1. Have hobbies, interests, or work that interests you, which can be done with other people.
2. Search for groups, spaces, or jobs in your area that do those things. If none exist, make a group/space and advertise it somehow.
3. Consistently attend regularly scheduled gatherings.
4. Talk about things other than the thing sometimes when you get together.
5. Do this for a while. You now have friends.

Note that this works best when the activity requires some kind of teamwork, group effort, communication, or shared work/suffering.