It can be a challenge getting started, for sure! Distance combat is your best friend... offensive spells and bows will be very, very useful
And as Radek pointed out, you can keep re-entering town to recharge your mana. Just be warned that the monsters heal up as well... be sure to kill at least one before going into Valeia.
You can also fight from the gates. Once battle has started, they *WILL* hunt you down. So you can battle from the right gate, enter town, and then exit via the left gate. WAIT.... the critters will be heading from the right gate to the left gate to battle you. So you can heal up, equip your armor and such (you *have* done that, right? Not that I've ever forgotten...
), and recharge your mana while they come back over.