Can you share your config? Have you enabled substitutes (see here)?

You can look at mine here (it’s pretty small): https://codeberg.org/mrh/dotfiles/src/branch/trunk/guix/system-config.scm

That’s my personal config so you probably don’t wanna copy it verbatim, but it should show you how to do a minimal setup.

I don’t use gnome, but to have gnome just add (service gnome-desktop-service-type) to the services field, and replace %base-services with %desktop-services. It might complain that you have some duplicates after that last step (since I add e.g. elogind service myself, but %desktop-services already has it), but when it does just do exactly what you’d expect and remove the duplicate service. See here for more info.

I also have a few things in there from the nonguix channel, including setting up their substitue server, so be aware of that when copying things.

My config also is setup with an encrypted drive and a swap partition. Again just take the things which make sense and ask about any specific questions you have.

Also note that you should generally install most packages, like kakoune, at the user level, not the system level.

Finally I would recommend joining the IRC channel at #guix on libera.chat. It is very active and people there are always answering questions.