Or go to user groups, check them all out (these are the clans

You can see a short message and who's a member etc.
If you find any you like then message the 'leader' and ask to join. Some are open for all, some only let people join from a specific rank up, some just ask you so be a 'nice' person

others will post youre request in their forum and let people already a member have a say etc.
Just play some games first scope it out and then apply for a clan (i wouldnt create a new one yourself yet not to mention that its not possible at the moment)
Also while you play games you will meet alotta peoples, talk to them nicely and they will be friendly aswell and quit a few will be in a clan, so who knows!
Good luck!