Caching on site with ACF Custom Post Type Relationships

I have a small niche WordPress site where registered users enter data through forms on the site (or the WP Rest API through a mobile app). Currently I do not have a caching plugin. On the site, the user creates custom post types through these front-end forms. You create a "series" of tournaments, "tournaments" and "entries" in these tournaments. There are ACF relationship fields between tournaments with a serial ID and entries with a tournament ID. In other words, a series is a collection of tournaments and a tournament is a collection of entries.

Each tournament has a page with a template that displays all the tournament information and each entry in a list. When a user adds an entry to a tournament (creates a CPT for the entry relating to that tournament), he has not really changed the tournament.

How does a caching plugin know it invalidates the cached page for this tournament? Maybe not, but doable? The number of entries and details of the entries displayed on the tournament page must be updated.

What options do I have to enable a kind of caching here? This seems to be something that has to appear often, but I can not find much discussion and have never dealt with it on a dynamic page.