The old world zones, that being kunark, velious, luclin and even PoP to some extent, are largely deserted now-a-days (I know that PoP doesn't apply to your level). So I have to disagree with the above poster in saying that you can get a group in something like Kurn's tower. But doesn't mean you can't, and during certain times I have no doubt that there are people in some of these old world zones. But I find it highly unlikely that you'll get groups in these zones with any consistency.
But he was right is saying that PoK is a place to sit and LFG. Really anywhere, with the LFG tool. Players can search you out from anywhere in EQ. There is nothing wrong with Paludal Caverns. The xp is great, and you're more likely to find a group there.
Of course, there's also Monster Missions. That seems to be where a lot of the lower levels tend to hang. There's some animosity from the player base concerning these missions. But you can group with someone of any level and get really good xp (of course really good xp is relative). Check out the thread near the top of the list in these forums, called "Monster Missions-The Master List".
I will say this, if you end up going the Monster Mission route. Be sure to group and xp in other normal zones with your character as well, whenever you get the chance, such as PC. Make sure to keep his/her skills up to par. Such as offense, defense, spell skills, ect.. Evidently this is a concern among many of the higher level players, in that they're seeing people leveling all the way up to 70 on MMs and having no skills, spells, and gear. Learn to play your class.
But in all honesty, the best place to find groups for your level is in the zones that have MMs. Try HHK, thats the latest, hottest MM, for now anyway.
Sadly I suppose, the game really doesn't start until you're in your 60s. The older expansions are lifeless. You may be able to find a family type guild, that has levels similar to yours and want to group in some of the old content as well.
Good luck.