You should have not only an idea, but you should realize clearly all the mechanics. A minor background in art would also help you with the presentation of your game. Business would also be a good degree to study (or business administration, or something like that) so you can administrate your own business. As for the realization of the technical part, I'd recommend you to contact a talented team of python developers C, C++, C# developers.
I would also advise to start with something simple, do not to create something massive at once. Create so-called minimum viable product of your game and test on the focus group. This way you could prevent yourself from significant losses of time and money. You should hire a good marketing professional, who could help you with entering the market.
I'd also prefer not to contact the consulting agency, but I would find some connections among real game founders who've got successful products under their belt and conduct coaching/mentoring based on their practice.
