There is no planning or concept involved, and that’s a big team you’re asking for. A team that goes to high numbers without an established base of trust or knowing of one another can lead to various problems.
First thing you need to do is plan out what you want. What is the game going to be? What is the skeleton - the core that needs to be established to make this a functional beginning? What is to come afterward additionally?
^ Don’t actually answer those questions, that is some food for thought.
Also, remaking SCP:CB is an easy task that can be done with a team of 3 or less. wubzy301 successfully recreated SCP:CB with a team of two. Chunking on your team means more demands, more expectations to live up to and much more to manage. The stress isn’t worth it.