Setting up TOR:
You don't have to use TOR, but it's a good idea if you're into privacy. I'm putting the TOR instructions here because I chose to set up TOR after configuring BitcoinCore and downloading the entire blockchain, unfortunately my node is not connecting through TOR so I suspect that if I had done these steps at the beginning instead of the end then it may have worked. If you want to reference the site where I found these instructions, navigate to https://stadicus.github.io/RaspiBolt/raspibolt_20_pi.html and see the section on Privacy. Or you can just skip the TOR section.
$ sudo nano /etc/apt/sources.list;
This will open a file you need to edit.
$ deb https://deb.torproject.org/torproject.org buster main;
Add this line after the existing line.
$ deb-src https://deb.torproject.org/torproject.org buster main;
Add this line after that then press "ctl+x" to exit, "y" for yes, & "enter" for yes.
$ sudo apt install dirmngr apt-transport-https;
$curl https://deb.torproject.org/torproject.org/A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89.asc | gpg --import;
$ gpg --export A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89 | sudo apt-key add -;
$ sudo apt update;
$ sudo apt install tor;
$ tor --version;
This should return "Tor version 0.4.1.6." (or higher).
$ systemctl status tor;
Press "ctl+c" to exit.
$ cat /usr/share/tor/tor-service-defaults-torrc;
This should return a few lines with "User debian-tor" in them.
$ cat /etc/group | grep debian-tor;
This should return "debian-tor117:x:" or something similar.
$ sudo usermod -a -G debian-tor pi;
My user is "pi". Use whatever user you set up. Or if you left it default like I did, enter "pi".
$ cat /etc/group | grep debian-tor;
Now it should return "debian-tor117:x:pi"
$ sudo nano /etc/tor/torrc;
This will open another text file you need to edit by removing the hashtag signs (#) from the following lines (You need to scroll down to find them).
Uncomment:
ControlPort 9051
CookieAuthentication 1
Add:
CookieAuthFileGroupReadable 1
$ sudo systemctl restart tor;
Now restart your Raspberry Pi.