I’ve applied the changes and I still get the same errors as latexindent is unknown in the PATH. I don’t think it’s worth trying to insist on it, as compiling latex locally isn’t essential for me. It was simply a convenience not to have to use online editors like overleaf in case I didn’t have an internet connection. Inexplicably, on both fedora debian and windows, I’ve never had to do anything other than install the distribution and the appropriate extension in vscode to compile latex code without a hitch. I’ll keep checking the thread in case anyone has had the same problem as me; in any case I thank you all for the time you’ve given me.
I think we still don’t know what your $PATH actually comes back as …
but we don’t need to know - you do. 
addendum:
You installed the full thing and installed it system wide, as I understood it.
So: why not set the PATH to it system wide as well?
Here is the last lines after installation finished:
Add /usr/local/texlive/2024/texmf-dist/doc/man to MANPATH.
Add /usr/local/texlive/2024/texmf-dist/doc/info to INFOPATH.
Most importantly, add /usr/local/texlive/2024/bin/x86_64-linux
to your PATH for current and future sessions.
Logfile: /usr/local/texlive/2024/install-tl.log
Now set the PATH.
This works:
sudo nano /etc/profile.d/texlive.sh
put this in:
# self explanatory
append_path '/usr/local/texlive/2024/bin/x86_64-linux'
export PATH
This will append texlive to the PATH.
Or
prepend it, like the website install instructions say:
sudo nano /etc/profile
add this as the very last line:
export PATH="/usr/local/texlive/2024/bin/x86_64-linux:${PATH}"
I do not know the reason for why they tell you to prepend this rather than append,
so here are both variants.
Good luck!