You can search for the Debian/Ubuntu package that contains a given file with
apt-file. For example,
apt-file find "t1qpl.fd"
If you’re not sure about the exact filename, you can do a full-text keyword search with
apt search, or a regular expression search for filenames with
apt-file find --regex. For example,
apt search Pagella points me to
fonts-texgyre, which contains the OpenType version of TeX Gyre Pagella, and
apt-file find --regexp "[pP]agella.*\.otf" finds three packages that install different versions of it.
You can also search your distro’s package repository online, in case you need to install a package for a different OS version.
If there is no apt/rpm, you can also do a filename search on CTAN, to find a TeX Live package you can install to your local tree.
If all else fails, you can download the files you need to a directory where your utilities can find it, such as: the directory for your project,
$TEXMFHOME, or for TTF and OTF files,
/usr/local/share/fonts/. It’s a good idea to put them together in a subdirectory, since your computer is not keeping track of where each file is from, new versions, or conflicts.