How to install Linux Packages (start with Debian)

My main laptop is a Lenovo Thinkpad T480. I want to set up a ZFS with UEFI boot.

I also have another laptop, Dell Inspiron which is a BIOS/Legacy which I also want to try ZFS.

There are some Linux packages I probably want to use, such as a note taking app called Obsidian. I might try to find an alternative. But I still feel I need to find a way to install Debian packages just in case I need something which can’t be found within the FreeBSD packages.

I am still very new to FreeBSD so I don’t really understand how to install Linux packages. There are a bunch of background steps/foundational knowledge that I don’t have which makes it a little overwhelming for me to figure out.