I did the tutorial dungeon, added a 3rd member to my party and ran around town for a while getting a bunch of quests. But any time I try to venture out of town, my part is basically insta-killed before even 1 round of combat finishes. Tried going one way along the beach and was ambushed by orcs that killed my guys real quick. Went along the other beach and ended up getting ambushed by a pack of wolves who also instantly killed my party. Is there something else I should try?

Follow the MQ and other town quests until you get close to level 4. There is a good legion quest just outside the east gate for good XP and no fighting. (old church quest) When at or near level 4, go out the north gate for lower level enemies.
The beach and south areas are higher level.

Thanks!

Add a 4th party member as well

Actually, the enemies outside the north-east gate are lower level than those outside the north gate. That's probably the best place to start after you're done in town. (And under town. Don't forget to search for tunnels.)

The other thing to do is to practice the combat system, and especially the magic system.

A few tips:

1] Orcs are bloody tough. Avoid until much later.
2] Undead skeletons are resistant to most weapons and all poison. Bring clubs. Or better yet, use magic. Daggers and normal arrows are -not- going to do much good. And you'll be fighting lots of these.
3] Account for the environment. It's raining in the northeast, so exploit that with lightning and frost spells. Counter the fires to the north by bringing rain magic of your own.
4] Crowd control is king. Get spells and abilities that knock enemies down, that stun them, blind them, charm them. This will make fights much, much easier.
5] When levelling, don't focus too much on one or two basic abilities. For the price of raising two magic skills to 5 ranks, you could raise all five to 3 ranks. The latter option is much more versatile and (i.m.o.) fun.

Magic actually could fill a few chapters by itself. It's the most fun and the most useful part of the game, though in later chapters weapon damage catches up (and possibly overtakes) it. It's a good idea to have access to all types of magic, possibly on more than one character. All you need is half-decent intelligence of 6-8 or so (But no higher, or your main stats will suffer too much. You can always use items to help out if it's still too low.) and 1 or 2 ranks in a few magic skills. Sure, your fighter is never going to be a fire-ball tossing genius, but he can certainly cast some good buffs and/or utility spells. Better than twiddling his thumbs whilst the enemy is too far away to smack, and it'll only cost you a few skillpoints.
It's a lot of fun to have your wizard teleport an enemy right next to your rogue, have the rogue backstab him a few times, and then have the fighter teleport him back out of reach before his turn comes around. Or to have the fighter cast rain so the wizard can then use ice to freeze the enemy in place, or create a frozen surface that will send charging enemies falling.