Hi aireal1996,
Welcome to the Apple Community.
We are all Apple users like yourself, doing what we can to help each other troubleshoot.
Apple products / software are always changing / improving / updating, and do take some keeping up with !
In general, they reliably work just the way we have set them up / or / in the default manner, from the store.
Apple support have an article online:
Use Touch ID on iPhone and iPad
(NB: Seems most people use a finger ... (a thumb is generally bigger than the Touch ID surface ?)
https://support.apple.com/en-us/HT201371
And
"Use Guided Access on iPad" may have some tips:
Eg: Display Auto-Lock:
Set how long it takes iPad to automatically lock during a Guided Access session.
Complete article: https://support.apple.com/en-au/guide/ipad/ipada16d1374/ipados
Also:
Here is a link to the very useful, online iPad User Guide (It doesn't come "in the box")
(You can click on "Table of Contents" at the top of the page that opens,
to view various topics, leading to detailed articles.)
https://support.apple.com/en-au/guide/ipad/welcome/ipados
If needed:
There is a "Get Support" Link to Apple at top right on this discussion page.
All the best :-)