What is guided access and can I use it to lock down my iPad?

Guided Access helps you to stay focused on a task while using your iPhone, iPad or iPod touch. Guided Access limits your device to a single app and lets you control which app features are available. Importantly, you can use Guided Access to disable the Home button when using TD Snap® or another desired app to prevent users from exiting the software.

Guided Access (iPadOS)
Follow the steps below to use Guided Access to only allow access to TD Snap® or another desired app on your iPadOS device.
Guided Access Initial Setup
1. Go to iPadOS Settings > Multitasking & Gestures and turn OFF the following settings:
– Four & Five Finger Gestures
– Swipe Finger from Corner
2. Go to iPadOS Settings > Accessibility > Guided Access and turn ON Guided Access.
3. Select Passcode Settings.
4. Select Set Guided Access Passcode, then create the passcode that you will use to quit Guided Access.
Start a Guided Access Session
1. Launch TD Snap® or other desired app.
2. Triple-click the Top or Home button.
Optional: Circle areas on the screen that you would like to disable.
Optional: Select Options to access additional settings such as Time Limit and disable hardware buttons.
3. Select Start.
Quit a Guided Access Session
1. Triple-click the Top or Home button.
2. Enter your Guided Access passcode.
3. Select End

Here is the full article from Apple
https://support.apple.com/en-us/HT202612