Notifications

Ok guys. I am looking for some help and direction. I am new to coding so I apologize for the stupid questions. Here is what I’m looking for.
So I run a dog daycare and on my website I have an employees only area. In this area I keep an electronic copy of my dogs records. What I would like is a way to get an alert style notification when a vaccination has passed it’s due date on a dynamic page. I know it’s probably confusing so I’ll try to explain a bit more.

I have one page that is an intake form that allows for user input using a date picker to list the expiration date of a dog’s vaccinations. The dataset is connected to 7 dynamic pages but 1 that specifically interacts with the vaccine information.

So 1 page (dynamic) lists the 3-4 relevant vaccinations, and an integrated google calendar a second page is a repeater that lists each dog’s main items. On this page I would like an alert to show up when a vaccination is past it’s recorded due date.

Hopefully this makes sense. Is this even possible? Can someone point me in the right direction to even start researching this?

thanks!