macAilpin: There is no order of quests. If a certain quest is too tough, run and come back after you increase your skills. If you feel lost talk to the Seer who is located on the Harmondale Map in M&M7 and the Ironfist Map in M&M6 . The Seer gives what you need to complete the main storyline. But when you decide to complete this main quest is up to you. (There is some timing in M&M7. But it is pretty loose.)
Edit for misspelling
Excellent advice and the only way to play these games. The worlds are so huge and the cast of characters and quests so vast that at times "Where do I go now?" can seem an intimidating question. This is a game of exploration and trial & error, to some degree. If you get smashed in one place, reload and go somewhere else until you find fights that you can win. Biggest virtue: patience...;) Best practice: Save often, save everywhere...;)
It takes a while to build your characters--be sure and concentrate on finding and completing promotion quests for your characters--many abilities and skills and spells aren't available prior to your promotions, etc. Good luck! Nothing satisfies like these games when your characters finally start mopping the floor with your foes...!
One bit of free advice to get you started: if possible, make sure that every member of your party starts the game with a bow skill! Really not optional in the beginning. Also, in MM7, *be sure* and experiment with combat in turn mode...! In fights with multiple enemies it can make a huge difference. In small to medium fights you can go all the way through in real-time mode at a certain point, too. Lots of fun when you learn how to play the game!!!
I'm replaying MM7 again (3rd or 4th playthrough in the last decade--can't really remember.) I just finished MMX and before that MM6. Also plan to play MM8, MM9 again, too!
Then I may go back and give 1-5 a crack as well....;)