You can search profiles to find like-minded users, or invite your existing friends to join!
Another way to find friends is to browse your profile calendar and see who has been visiting the same concerts as you have. You might find people who you have run into often without even knowing so, or find an opportunity to chat them up by talking about the band(s) you have been seeing or are going to see!
Of course you can also just look at profiles and add friends indiscriminately, it's up to you!
This site is however still new so inviting people is currently still your best chance to 'friendwhore'.