Interactive RW website

I’m interested in creating a new website for my consulting efforts that would allow inputs into the website from the user and save those under a unique ID/ PW for that user. I think in terms of an Excel page for data collection. Initially, it could just be to allow me to grab the data and run it through my proprietary algorithms for feedback to the user. Ultimately, I would like to embed protected algorithms, so the user could “game-play” on the site. I seek to provide the user with valuable insights to their strategy planning for medium-sized businesses, startups, or operating divisions of larger corporations.

Any suggestions regarding how best to accomplish this? Thanks in advance for any guidance you may provide.