Hello there! Glad to see another person interested in modding, it's a fun and rewarding experience!
I'm going to be honest: It will be hard for you to find anyone interested in helping, especially if you don't have a main skill (spriting, composing, or programming). The term "idea guy" is a running joke among many modders because of how many people try to make mods but only
contribute ideas. Although creating a mod as the "idea guy" is possible, it's not common and requires impressive leadership skills. Finding devs is hard even for those who can code. The majority of modders have settled into a main few mods that they dev for and don't do things outside of their main mod for the most part. Even if they're not busy, most experienced modders are aware enough of their talent to charge for it, so if you don't have a budget it's much easier make a mod by doing the heavy lifting yourself.
With that said, it is true that there are some individuals who go from mod to mod and contribute sprites or code for free. I am one of these people, and I will warn you that our standards are generally high. We don't like to see our work wasted so we generally only contribute to mods that we believe have potential.
So, I would recommend putting all your plans and ideas in one spot since it's easier to get devs to help with your mod when they understand your vision. Spend a lot of time refining your ideas and avoid content for the sake of content (bloat). From there you can pitch your concept to coders or spriters who might be interested in being a part of it. An example of someone who is incredible at this is Egshels, the owner of a little mod called Starlight River. They have high standards and a love for uniqueness, quality and fun that shows in everything they create. I would recommend checking out the discord server of their minecraft mod "FundamentMC" so you can see the process behind how they create and share their vision. And they're not the only one, the tMod community is full of talented leaders.
To reiterate, I'm not saying you can't make a mod as "just" a leader, but to do so you have to take that job seriously. Good luck with your mod and feel free to let me know if you have any questions!