Help needed deciding what to build

Hello IH,

I'm getting back into the Indie Hacking game after a break!

I have an idea to launch a platform that helps founders validate their product ideas before they start coding. It's in the early stages: https://productvalidation-fe.vercel.app/

I'm trying to figure out what the core feature is and what I want to work on first.

Some possible options

1. Allowing signups to make feature requests
2. A way for signups to give feedback on the product/idea
3. A way of creating votes, eg vote for designs, features
4. A survey that is automatically sent to new signups to get better insights about what their needs are

I would be grateful for any feedback on what part of launching an idea founders struggle with the most and if any of the above (or another suggestion) can help.

Thanks,
Marilyn