I’m going through this exact process with one of my own projects. I’m already learning things that will completely change the offering.

I agree that you want to reach out to potential investors, but make sure you have some sort of confidentiality agreement in place. Admittedly, you may struggle to actually enforce it if breached, but it could protect your idea if it’s especially novel. What you’re really looking for is somebody who can pressure test your idea for you. Investors have heard countless ideas and seen companies fail in every possible way. Their questions and feedback will highlight the risks and assumptions buried in your idea.

With your risks and assumptions out on the table now, you’ll want to run tests and experiments to validate and mitigate. There are entire books on this subject, so I won’t try to reproduce that body of knowledge. Depending on your skill set and how you want to test your idea, you may need to contact some freelancers to help. As just one example, you could test demand for a consumer product by creating a barebones e-commerce store and set the item as always out of stock. You could even pay for Facebook ads to test your messaging. Depending on your familiarity with doing these activities, it may be worth paying somebody to do it, especially if you’re prioritizing speed.