The easiest way to become a member is to invite your friends to join you in Bloody Roads, California. On the menu on the right you are able to invite them via mail, facebook, or whatsapp (only iOs).
Tell them how to build a “church” and to join an MC. Then tell them the name of your MC, so they can apply for membership. It’s so much more fun to play the game with “real life” friends.
Besides that, you can search for players via the reports, ranks or the search on your friends’ page. On the profile page you find a lot of useful information about that player and you have a contact button to send the player a private message.