Look into verifying PGP keys before you get too involved, also obviously never download anything off tor.
As for discussions, people used to confess stuff on certain questions on here, it wasn't super common though. Other than that, there's forums like Dread (down atm), BreakingBad, and plenty of other forums, you can use TheHiddenWiki or Torch search engine to find some of them.
Here's the link for torch:
torchdeedp3i2jigzjdmfpn5ttjhthh5wbmda2rr3jvqjg5p77c54dqd
As another rule of thumb though, don't open any random links either (I realize that's ironic to say now)