Campaign variations

[DMreaperWill]

I understand from my extensive research(roughly 2weeks worth of time and growing) that people have put a multitude of campaigns out into the ever growing and expanding world that is D&D. My friends and I play the tabletop version and it's never a dull moment for the adventures and yet the role of DM has me the most fascinated of everything up to this point in time. Long story short is I wanted to make my own campaign but I'm stuck debating on a few things that have me so hesitant and torn that it's actually causing me to get downright aggravated and even slightly stressed out. I'm considering a higher level cap, slightly different multiclassing options or expanding the existing classes, and lastly is if I should add an NPC/NPCS to their adventuring group or make a rival group as motivation so to speak. I would greatly appreciate any advice or constructive criticism I can get, please and thank you.

[DMreaperWill]

Demons and Devils against the celestial. The 12 astrology zodiac signs and their dark counterparts The 12 Black Zodiac. Greek, Egyptian, and Norse deities formed a Triad. The unforgiving wrath of Odin the destroyer with his 3 children Thor, Hel, and Loki. Creator and Destroyer guardians of the Devourer of Oblivion, a trio of weapons wielded by Greek titan Chronos reincarnated inheritor of the power of Anubis.