First, just to be sure, you are (S)earching after every fitght, correct? That's how you'll find most of your money and items in the game. Make sure to have your robber open the treasure so he or she can disarm any traps. If your'e injured, you can rest first, as long as you don't leave the square you're on. If you leave without (S)earching, you will lose the treasure forever.
The beginning is always a bit of a grind, but you should have enough money to train, just from what you find after killing monsters. As for equipment, you can always take the equipment off of the starting party and give it to your party. Just go to the inn, sign in with half of your characters and half of the pre-made characters, transfer all their stuff, then repeat with the other half and take their stuff too. That will give you a good edge in the beginning. Honestly, after that you will start finding much better equipment than you can buy. You should save gold for training.
I assume you are still exploring Sorpigal. When you've mapped it out, try exploring the dungeon underneath the town next. Enemies there are slightly tougher but will also drop more gold.
Train your characters as soon as you can affford it, because gaining levels makes a BIG difference in being able to fight effectively. If you have to choose whose level to raise, prioritize getting your spellcasters to level 3, because this will unlock the second tier of spells, which are very useful.
So I guess there isn't really a quick way to make money early on, just keep exploring and fighting and saving often and once you've gained a few levels and can start exploring the world in earnest things will pick up.
Have fun! I enjoyed the game much more than I expected... it gets really good once you're strong enough to leave the first town and go exploring, so keep at it!