One thing I've noticed is that I can't found party to dungeons by the shortcut N. Why is that?
I quickly learned that as well. The only dungeon that gets any play is the Osiris dungeon and people run through it quickly to kill mobs as fast as they can for the XP. It's a levleing up dungeon. Most players don't even gather drops as they go. The rush through in a preset pattern, avoid all the bosses, and then once they get to their unofficial end point, they use a Dungeon Wing to escape out to the entrance and then wait for the dungeon to reset before heading back in.
I've done it and its a wild ride along the way but it gets boring fast. And when you hit ML 24-25, you don't get any more XP doing it. You have to switch to the Darkwhisper, which has monsters that HIT VERY HARD. And you can't face those critters on your own until you get over, at least, ML30 and even that would be tough for some classes.
Players rarely do quests. It's frustrating because I like doing the quests and it's tough finding anyone who doesn't want to just grind out XP vs. Khepri (in Forgotten Payon) or hunt for solvents so they can make high-powered runes so they can be tougher in PvP battles (which I'm not interested in).
Most of the stuff that comes up when you hit 'N' seems to be people looking for a boost or they are using it to attract clients for their Vendor shops. Once in a while you do see groups gathering for a high-level raid but most of those players are ML35+.
You can try to get into a guild, but if that guild is a PvP guild, you'll end up doing nothing but PvP battles (I assume). There are PvE guilds too. Look for them under the Find Party option in the chat window. People also post that they have a Social Guild, which sounds to me what you're looking for. I doesn't come up as often, but almost no one used 'N' for what it is intended. (The chat window is the best way to communicate what you're looking for.)
All the high level ML players tend to hang out around the Kafra Auction Service femmes in Prontera and in Morroc. Usually on Channels 1 or 2. The area around the Kafra ladies in Morroc on Ch1 is congested with players who set up their Vendor stores. It causes tons of lag when trying to go through the area. I advise being on one of the higher channels when you have non-Vendor-related stuff to do while in Morroc. Don't get me wrong, the 'goldies' are worth going to when you need to Refine or Hone something with lucky/blessing power and the occasional Infinium stone gained through events (or bought through RO2's Kafra Store).
If you want a friend, look for my main character in game. He's a ML28 rogue named Mesik. I have another character too (SirMojoRising), but I rarely play him. Of course, he's only 10th level, so if I hit a wall playing Mesik, I'll probably switch to Mojo.
Good luck and see you around Midgard,
Cheers!
Knightfall
I don't even have full confidence on my english to do this.
I don't know nothing about master level yet, guess I'll learn soon, since my main character is 42.
I got full confidence doing this on Grand Fantasia, do you know? I made a warrior, got her full build (oh, the golds spent and farms and all the suffering...) and then spended most of my time online in pvp arenas. She was so strong, no one could beat me alone. I miss her so much 
hope I can be that strong here too.
