I don't know if the game is more popular on the East Coast, or what, but pretty much every guild I've ever been in goes by Eastern Standard Time. However, you can absolutely join from any time zone ... you just have to do a little math to get the time of scheduled events correct.
As for finding a guild, I'd check out
https://wiki.project1999.com/Green%20Guilds. Given your low level, you probably should focus on the Casual Guilds section.