some suggestions

[GM-Pandora]

Many of the well established guilds have chosen a city other than prontera as their "headquarter", so you may see people in those city. Officially as a GM we don't tell players where to go, of course Prontera has lots of NPC which makes it a convenient place, in addition it's also a social hangout. It would be hard to split the socialisers in different cities.

heRO has many events aimed for everyone, be they novice event or RP, those are usually fun to break the daily routine. There's also lots of unique quest you can try. There's fishing, there's mining, Zodiac quest, Flower wing quest, etc. Or ask on @main if there's someone in your range to party with, it doesn't feel as much like grinding if you find someone to do it with and interact.

Thing is, most players do not stay between 40-70 very long, either because they get help or because they are used to the game and level kinda fast, so sometimes it's hard to cater to the need of players in that level range.

There are many awesome guilds, I wont name you any, I'm sure their respective representative can come and give you more info themselves ^_^