Welcome! ChelonianEgghead covered all the stuff you'll need to know in his post, so you're good there.
I'm awesomedude, your friendly neighborhood moderator. The rules are pretty basic stuff, so the only other thing I would recommend is to check out the myriad of fan projects! It's a little outdated, but the fan projects directory (http://www.chexquest.org/index.php?page=page133) is a good resource.

Hello and welcome aboard the USS Zorcher!    To your left you will see the majestic, yet endangered, Nerd Whale, it's numbers are slowly declining due to jocks harpooning it for it's lack of meat and lack of fat. Be sure to read the board rules if you can find them, check out the fan projects at http://www.chexquest.org/index.php?board=53.0 and hang out on Discord at https://discord.gg/saAceDH

Just a few things you should know:

1). Avoid the West Wing at all costs because there have been sightings of evil purple lampposts that will eat your soul.

2). Always carry ginger ale with you to ward off the purple lampposts. THE WEST WING IS STILL OFF LIMITS.

3). Never, EVER feed Loremaster after midnight! Just don't!

On the topic of new missions, you're probably aware of Chex Quest 3 at http://www.chucktropolis.com/gamers.htm An old user named xbolt made a three-episode mod called "Newmaps" available at http://xboltz.net/newmaps.html The Ultimate Chex Quest is a project by Boingo the Clown to create a 4-episode IWAD consisting of the original two Chex Quests and 22 original levels (no secret levels, sadly) to create what a full-fledged Chex Quest megawad could have looked like, with a number of modern enhancements. You can download it at http://www.doomlegends.com/chexquest/tucq.html Unfortunately only the original two games are included in the current release, but work is underway to at least expand the first episode to 8 missions, and it shouldn't be too hard to convert an old submission into an E2M6. Strife also made some really good levels which require TUCQ to run, of which you can find an updated version at http://www.chexquest.org/index.php?topic=5332.msg195627#msg195627

Nowadays you can run GZDoom natively on Mac and Linux. Just go to the download page on either OS and you'll get the appropriate installer/package.

When I first played chex quest the first version, I absolutely loved it! I got tired of it eventually of course, but less than 10 years ago, I play it on and off for fun every six or so months.   I hope you guys plan to make three new episodes in the same design as the old ones. With more levels of course...

ps, I appreciate that your game has no crazy requirements to play.

I have a 1st gen Kindle Fire, but am having trouble finding a good source port that supports Android 2.3.4 and doesn't just crash on startup. Any thoughts?