The release notes are posted for Unity 8, I would take a look at those for upgrade information. As far as the new TSP, the new software should install the new 8.4 TSP, so no need to install that. You'll need to obtain a Unity 8 upgrade license file:
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...