I cannot find the exact commands to type in the terminal to find my latex configuration files and where I should put additional downloaded latex packages in case I needed them (I do not even know where they appear when you download them from the web). I am sorry for my ignorance, but could someone help me about it? Thank you for your attention and have a nice day!
There is a nice tool
kpsewhich. On my machine I have
kpsewhich -var-value=TEXMFLOCAL /usr/local/texlive/texmf-local
This means that my "local" TeX tree is
/usr/local/texlive/texmf-local. A downloaded (local in Unix parlance) LaTeX package on this machine would go into
You can find more information about the way TeX searches for files here: https://www.tug.org/texlive/doc/texlive-en/texlive-en.html#x1-530007