Suggestion on how to prototype this project

I know this a very general questions, but we can't stop thinking about it.

We want to try to test the validity of a project without putting too much time into it. We have 3 months worth of time, 4 hours per day. 2 of us.

Question. How would you test this idea? Tools? back & front end? Frameworks? Form builder?

The project is online wills.

Customer would create an a will by answering a few questions- to save, export, or print the will they would have to create an account. They can login if they want to make any changes.

So far we were thinking about just picking one State that has simple inheritance laws as compared to other states, tailor the will for individuals and not estates, create a landing page, and simple database. Test various landing pages and paid ads.