3 sided Marketplace mvp

I am searching for “the best way” of building a marketplace with very specific features. I would like to get some ideas/advices. I tried by using Wordpress (wocommerce) but not succeeding with any of the themes I tried so far (I liked the marketplace them from Buddy Boss but not always working like it should). . The marketplace I am trying to build have 3 sides: vendor, costumer/buyer, and charities. This marketplace have to focus on local shops so I need to add geolocation recognition. By buying on a local store each costumer (and by each transaction) can vote for one of the local charities (projects that also charities kan place on the marketplace so also needs his own place on the cms). Every so much time the most voted charity wil get a portion of the earned money. The goal is to help local stores and to help keep al the public services (music, sport clubs, playgrounds, etc…). The spirit is to build a kind of backup for these store owners so they kan keep their stores open by adding online services. On the future also possible to add some B to B features (communicate with each other and make bigger stock orders) so the vendors can work together (things like dropshippping). So, wat doe you recommend for this project? Wordpress, Magento, own cms??? Build my own theme?? I really need to make a MVP for this startup so I don’t want to spend much money here right now.
thank all you in advance