Can't seem to do a Browse Host
 

I click on a song and then on Browse Host. The little circle goes round and round then stops but nothing happens. I tried 15 different songs and 2 times I got a "can't browse" sign, the rest of the time nothing. Why??

Browse Host isn't reliable. One minute it will work, the next it won't.
You're most likely to have success if you browse somebody who has chat enabled. You'll see a smiley in the chat column. If you don't have a chat column showing, right click on the column header of the search page & uploads window > tick chat. You should also have chat enabled;)

Try right clicking on a file > browse host, as well as using the Browse Host button. You'll have the best chance of success if you try to browse LW & FrostWire (Snow) hosts.
Just keep trying!