How to install programs in Linux? (Gallium OS)

[GunsMadeAmericaFree]

I just recently added a 480 GB USB SSD to an HP Chromebox, then set it up for dual booting, either to the original Chrome OS or Gallium OS, which I installed on the external drive.

I'm used to Windows, downloading an executable and double clicking it to install programs. So far, I haven't figured out how to install programs on Gallium OS. I would like to install
Firefox, VLC Media Player, and a couple of word processing programs. However, I'm just not sure what I need to do. I found something that looked like you could browse different programs,
and I found firefox. It actually looked like it was going to install, but then it just hung there, and nothing happened after waiting an hour. It actually made me feel like Windows might be more
stable, which left me feeling sad.....

Can anyone post a link that would give me an overview of the various routes for installing things in Linux? I appreciate it, since I'm just getting started with it.... I still miss the old days of DOS,
and checking my email with pine.

 

[GunsMadeAmericaFree]

Ha, I was able to get Firefox, VLC and 2 word processors installed this afternoon! Not sure why it hung up the first time I tried it, but it worked fine this time. This little thing is very peppy when launching Abiword, Libreoffice, VLC Media Player and Firefox. I'm very happy I spent the $50 on it, & that I spent the time to set it up to dual boot Gallium OS on that 480GB SSD. Chrome is nice, which is why I left it on there, but I did'nt like not being able to install local programs, or especially various browsers. I also wanted to be able to have icons on the desktop for several of the programs or websites that I used most often.