how should i go about building a site with these requirements?

I’ve been using wordpress for about a year now. I still consider myself somewhat of a newbie. But i have a big project and I’m not sure how to tackle it and need some suggestions regarding plugins or themes to fulfill the requirements.

The premise of the site is that the site owner will provide customers with daily diet plans. The customer will login with their unique password and be able to see their plans for the next 7 days. The site owner wants to be able to write plans for up to 2 weeks in advance, but still the customer will only be able to see it on a rolling 7 day basis. And to be clear, each customer will have their own unique login and ONLY be able to see their plan.

Any idea on what’s the best way to go about this? Please advise. Thanks in advance.