Ask HN: Recommended resources for finding and proving startup PMF?

[throwaway68102]

Looking to work on some new ideas after a few "failures" from which I have learned a ton.

Would like to continue learning, this time trying not to jump into a venture that does not truly have strong market viability.

Any resources on proving whether a potential business model has a market for it and furthermore proving it, would be much appreciated.

Thank you!