I would like to know what is the best option for accessing and controlling a Fedora 31 machine remotely using another Fedora or windows machine
or you may try https://cockpit-project.org/ - looks like a nice option!
If you want to control the graphical user interface, you can use VNC.
Settings -> Sharing -> Screen Sharing
To access this machine from another you can use GNOME Boxes or Vinagre.
VNC is notoriously insecure and fairly slow but NX over SSH is encrypted and compressed better than VNC. I highly recommend X2go but Wayland may be an issue.
how about chrome remote desktop?