Down loading apps is restricted on my iPad how do I turn off

Assuming that your iPad is not centrally managed by an Educational Establishment or Business (as the device may be remotely managed) - or is otherwise restricted by applied Parental Controls - if you are experiencing difficulties with adding, updating or removing Apps from your iPad, you’ll need to check your ScreenTime restrictions:

• Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Adding Apps - set to Allow
• Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Deleting Apps - set to Allow
• Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > In-app Purchases - set to Allow

try reading

Use parental controls on your child's iPhone and iPad - Apple Support