Any advice on black screen and screen locked for an iPad . It won’t let me do anything

See this, If your iPhone, iPad, or iPod touch won't turn on or is frozen - Apple Support

Make sure it is charged. Plug in and charge to a source you know it active for an hour or so.

You also may want to try a Hard Reset of the iPad

Firstly, hold down both the power and home button at the same time Continue holding both buttons down, the screen will eventually go blank The Apple logo will then appear, release all buttons. This will now restart your iPad and should fix any bugs you were experiencing.