Without any more details only very general advice can be offered. But that general advice would be to build an 'MVP' (minimal viable product) and start testing it. Test it with yourself, then friends, then family, then strangers, then more strangers etc. You'll be making changes to it along the ...
What your trying is one approach to finding investors. Here's another that in my experience is far more effective. I'd tap your network, and it's probably actually a lot bigger than you think! Linkedin is the perfect tool for this. Look for people you're connected to, that you trust, and that are...