Most large guilds (the ones that always manages to have a Trader in the same spot) are invite only and have a laundry list of requirements to be in it. Most others are there, they just don't actively advertise themselves and the game doesn't have a user friendly way of browsing the Guilds that are there. Everything is word of mouth.

I'm part of a small social guild, if you're a decent person, (and of "adequate age") I could shoot your gamertag over to the Guild Master.

Just go to every region and say in zone chat *lf guild.* I would suggest skipping the first region for each alliance (Glenumbra, Stonefalls, Auridon) and go straight towards asking in the second, third, fourth, and fifth regions (Stormhaven, Desheen, Grahtwood, Ali-kir, etc.) as you might get into a guild with an inexperienced GM in the former.

It isn't bad having inexperienced members in your guild but a new player acting as GM is painful as they just tend to use the guild to support themselves, while old players acting as GMs try to get a trading spot, organize something, and provide mats/gear to lowbies more often.

There's really only two types of guilds now days. Trader Guilds & End Game Trial Guilds. Idk if PvP guilds exist, everybody roles solo in Haderus. Either way, it is very hard for an up and coming guild. Especially a new PvE casual guild, even if the game lets you be in 5 guilds at once.