Some spoiler-free quick tips (so you don't have to learn the hard way):
1. The default party is fine, if you decide to make your own, be sure to have at least one sorcerer, cleric and either thief or ninja.
2. Get bows for everyone in the party that can use them as one of your first steps in the game. You will have unlimited arrows and you can effectively damage enemies before they can even touch you.
3. You can get temporary stat increases by giving donations in the temple, at lower levels these donations are just a few coins. Use this to gain the upper hand for tough battles.
4. To level up, you need to gain EXP as well as visiting a trainer and paying him.
5. Get the light spell for your sorcerer before you travel into dungeons.
6. A good way to get EXP is to destroy enemy outposts, they are just outside of the first town, I would get everyone in the party blessed in the temple before heading out to do this, though.
As far as the story is concerned, it will unfold early enough, just try to venture out and discover the other cities. I also really enjoyed Phantasy Star 4, one of the best 16 Bit RPGs.
MM3 is also not pure fantasy, but it will take a long time to reach this part.