Game Development from scratch

Hello I'm looking to make a desktop program from scratch, I don't know what the best method to do this would be. It is a platform for my art based game! at the start it should function with player log in, private messaging, forums, then later on listing things such as inventory, their characters, and interactive functions and places to explore. it should be compatible with a live game play option later down the line, we are working on pixel art, idk if you played league of legends but how they have the 'play' and then you go in to the game, we'd have a similar thing, so you 'play' and go in to the live action world rather than click and submit to progress. I need staff accessibility to access some content that they approve, and also paypal connected to the app! so that people can buy premium content. premium content being the ability to customise their own or character profiles, maybe html? and upload a custom avatar. also future additional content would be adding a gallery that players can upload art to, receive favourites and comments, and that designers can sell on. I can make visual mockups for sure no problems, I just need to find a programmer/developer that can work on this with me as a long time project, start out with a few things and then add things as we go! let me know if this would interest you, it is my long time passion project and I'm ready to take it further. - Fay