EIR at 500 Startups. Founder of PostRocket. My life: UI/UX + BD, Facebook + social marketing optimization, starting and helping businesses, and doing what I love as my job.
It'd be impossible to get a real number for this, but generally 700 out of 1000 real startups (not counting the ones not taken seriously by their own founders) fail completely. 299 get ok to good returns for founders and investors. 1 ends up like the Facebook, Instagram, Twitter, etc of the world.
I work with a lot of startups as an advisor or thru 500S. Figure out what the biggest value offering for your idea is, create the simplest product that only achieves that big value and nothing else (if this means you don't write code, then great). Get out into the real world and start actually charging people for that service.
Example is Instacart (3 hours or less grocery delivery on demand) when they were starting out (I imagine in a similar stage as you right now), went around shopping groceries and delivering it and charging customers via Square.
Most importantly, the reason you want to do this is to find out or realize that either there are a meaningful amount of people who will definitely pay for your service at which point you develop on custdev and product dev further or there aren't enough and you drop and move on.