There are daily quests that help you level. There should be a thread in the Guide section.

Maps will mostly be empty until you reach endgame. There's almost nothing worth running the low level maps for; maybe the Elites are an exception, given the new released APs. Plus, you'll never meet lvl61's (a good chunk of the players that do pve) when going random maps at lvl40, I think you'll only be matched with other level ~36-44.

Get used to the potions, you can't play without them xD.
There's a few mana pets that heal a bit, although I don't think people will be too happy about you using them. They're also too weak to really help you much.
The only exception is Mishi. It costs a little bit though, and you'll only break even after saving half a million mana potions.