First of all. This is not the [DARK WEB].
Simply it's taking back you privacy and keeping your anatomy safe. Just like you I also didn't know much about TOR.
So first step is to apps that may infringe on your privacy. Mostly GOOGLE apps. Go thru all your apps [PERMISSIONS] Settings! And SEE how much of your privacy you're giving up!
Those "unused DT entry" messages mean that either your app crashes or it generates lots of error messages. Probably Tor was cross-compiled with wrong or deprecated compilation flags. In my opinion the best is to enter a bug report.
This answer on Stackoverflow has more details about the message.
First, you have to get orbot
to get that on your phone there two ways which I know:
which is accessible from https://f-droid.org but before installing orbot you have to activate Guardian Project Official Releases under F-Droid -> settings -> Repositories.
which you just type orbot in the search bar and there ...