So, you're a mun, and you'd like to bring your characters to the CharLoft. No problem. They can walk in the front door and have a good time just as easily as anyone else. The information contained in the 'About the CharLoft' section should prove invaluable to learn more about the area, how to get to it, and how to have a good time there, whether your source character is from a modern Earth world or just that video-game-based panfandom you just can't resist playing in.
As you may already know, CharLoft is hosted on IRC through irc.darkmyst.org, with #CharLoft serving as the main IC channel, and #The_Loft serving as the main OOC channel. The game is more-or-less freeform, and there are some basic accommodations in mind. These are explained in detail elsewhere, but this is a quick summary.
Characters who enter the CharLoft may or may not recall their experiences there upon returning to their source world, at their player's discretion; likewise, they may or may not retain possessions taken from the CharLoft. After all, it'd be hard to explain to your gaming buddies that your elven shadow-walker picked up an Uzi while visiting an interdimensional cafe last week, and you'd like it added to your character sheet. (If your DM lets you, though, more power to you!)
Death is impermanent within the CharLoft; the closest you can get to actually dying is in being specifically banned from entry by the cafe owner. Otherwise, a character can return, even if killed (outside or elsewhere) within fifteen minutes, if their player allows. Whether they are any wiser from the experience is up to the mun.
The CharLoft has a habit of ceasing to exist - temporarily to remove problematic individuals by dropping them into the Void or into some other unpleasant locale (or just to dislodge them from their current position), or for a period of fifteen minutes to recover from major damage or to clean up messes. While no harm comes to patrons left in the lurch for the time this requires, being trapped in inky blackness for fifteen minutes because someone shot the barista is at best inconvenient and at worst highly disturbing.
Those who are capable of magics will note that their magics are slightly inhibited within the CharLoft - though mostly only so much as to reduce damage to the structure itself. Attempting to meddle with the Doors themselves is a Very Bad Idea, though, and may result in the accidental annihilation of one's character.
The CharLoft exists as a canon, and as such, one might not be surprised to realize that people will remember one's visits, objects put on display will remain, etc. How players choose to incorporate this into their own play habits is entirely up to them.
So relax, get along with your fellow players, and send your characters out to have a good time!