If you want to see CP and snuff films & illegal shit sure, keeping asking
Otherwise, I'd recommend not going close to Tor or FBI will fuck you up
TOR is a project by the American Government I believe. Or at least the Relay and nodes sustem is, you are legally allowed to use TOR. Using .onion sites is also legal only if you did something on there which incriminates your self would make your use of TOR illegal.