@Maxypun To change paths you use "cd".
If the code is stored in your
downloads directory you can change the directory with "cd /c/Users/yournamehere/
Downloads/homebrewcode"
If that path has a Makefile file you can build it using "make" from that directory.
Then a .3dsx file should be in there if there were no errors displayed in your shell.
It could be that you lack the 3ds sdk stuff at first, so if things may fail, you need to run "pacman -Sy" and then "pacman -Syu 3ds-dev" and press enter and y when asked for you action first.
3DSCraft and maybe other homebrew you want to compile may not t work with the current compiler anymore and as the maintainer of the devkitpro site has deleted all older version from his site, you would need to piece the missing parts together from
https://wii.leseratte10.de/devkitPro/ .
And as the structure of the sdk differed then iirc, it is really cumbersome.