I need some help getting started. I ventured into the first dungeon and died on some bats. I don't understand how to fight properly to stay alive, heal my characters, or even if it's incorrect to use the default characters at the beginning. What you do if a character dies? If anyone has a quick start or advice on how to begin the game, where I should be going, please let me know.

First of all, read the manual.

Some tips:
Try to roll characters that have 15-18 bonus points. It will take some time, but not too much.
One of your characters should be a Bard. With a Lute, the Bard has a free Sleep spell, which is a great help.
From the start go straight ahead to to a hallway with two chests. One of them will contain an Amulet of Life. You can use it to resurrect dead characters, but it has a limited amount of charges (7 or 9, I think).

This manual is… a lot of reading… Okay, page 1..

;/

Okay, I went through the manual. I'm still dying to rats, can't land a hit, and no idea where I'm going.

Equip your party right after start and save. Save often and reload if a party member dies.

The game has no auto-map, so it may be a good idea to draw your own maps.

Do you know why I can't hit anything? I'm dying to one bite from a bat or a rat, and my strikes are not landing. I have three fighters, one magician, one priest, and one thief. The thief fails at hiding most of the time, and if I succeed at that, it fails at striking afterwards.

I've heard the copt protection scheme of the original game would make your characters miss all attcks if you entered the wrong word. When the copy protection question comes up just hit ENTER, since the game is cracked.

Yes, I'm doing this. I don't miss every attack, just most of them…

Well, fortunately weapon skills increase quickly.
The most effective tactic in the early game is to have your Bard use his Lute on the most dangerous monster group.