Firefox and Chrome are not in the repo due to some security/licensing compatibility issues. However, you can download PureBrowser/Iceweasel which is based on Firefox and Chromium which is an open-source version of Chrome. For more info,
apt search iceweasel
apt search chromium
I set up Firefox/Chrome on my librem without any issues and posted it on this thread.
Installing chrome automatically setup the binary repo source, while firefox downloads and installs update when there are any.
I also documented my experience setting up a LAMP stack on my librem which you might find useful for setting up your apache server.
I wrote a lengthy thread on setting up a Librem which you may find useful.