Never done mythic dungeons or raids, next steps? I finished my current goal of getting the "mad world" achievement and I think I'm coming out of my noob phase and want to try mythic dungeons and raids. 

The guild I have been with is only a leveling guild that does not raid, so I have never actually done normal+ raids or mythic plus dungeons. 

So my question is, would it be in my best interest to join a new guild that focuses on dungeons and raiding? Or should I pug these things while I learn? I've never really used group finder for anything but have no attachment to the guild, so I am willing to leave in order to meet new guilds.

I'm a 465 ilvl rogue with pretty good corruption right now, if that matters. Also I have never used raider.io so I probably don't have a score on there.