Easiest way is to select "my tribes" from the sidebar on the front page. But if you'd like to see things chronologically (and really there's little enough content that there's no reason not to do this), you can view tribe posts by going to your "home" tab and choosing "tribe feed." From there, you're able to change your settings to see what you want, and you can also block snaps that are posted in certain tribes (e.g. if something was in /t/pics as well as /t/porn and you blocked /t/porn, you wouldn't see the post). I'm not sure if there's a control panel for blocking invidual tribes, though, you may have to do that on a case-by-case basis