What I suspect you're seeking is a way to mirror the app contents and app layouts and settings across both.
There's no means to mirror iPad contents, absent using a tool such as Apple Configurator 2, or some other MDM package. Doing your own small-scale deployment. This approach is probably more work than it's worth, and any change made to your iPad contents has to start with the MDM package and be reloaded into both iPads.
The brute-force approach here is to back up one, and then restore the backup to the other—basically, the same sequence as would happen with a migration from an old iPad to a new iPad. But that'll then start to drift as the two iPads are used, and you'll eventually need to keep one iPad as a "primary" as any changes to the "secondary" will be overwritten.
Schools do something similar, basically mass-reloading each iPad in a classroom with the same contents. But that requires setting up a fair chunk of management tooling, too.
In short, no good way to mirror these.