Don't Install iPadOS 13.5.1 If You Haven't Prepared
If you haven't prepared for the move to iPadOS 13.5.1 you'll want to hold off until you've had time to do so.
It's impossible to predict how your tablet will handle the move from iOS 12 to iPadOS 13.5.1 or iPadOS 13.5/iPadOS 13.4.1/iPadOS 13.4/iPadOS 13.3.1/iPadOS 13.3/iPadOS 13.2.3/iPadOS 13.2.2/iPadOS 13.2/iPadOS 13.1.3/iPadOS 13.1.2/iPadOS 13.1.1/iPadOS 13.1 to iPadOS 13.5.1. That's why we recommend spending a few minutes preparing for the move.
If you don't know where to start we've put together a guide that will walk you through the pre-installation process we typically use before we install new firmware on our iPads.
If you don't have a ton of time to devote to the pre-installation process, you'll want to at least make sure your data is completely backed.
Data loss issues are rare, but if you store sensitive data on your tablet (photos, game saves, etc), you'll want to make sure it's safe before making the move.