Q: How do I set up security so that I need to enter password every time I make a purchase at the App Store?  My son made several purchases at App Store by mistake because my Apple ID/Password was remembered on my iPAD.

Go into the settings, app store and have it require your password immediately

you can also enable restrictions and turn off the installation of new apps so that someone has to enter the restrictions code to install anything

I'm sorry.

Settings

General

Restrictions

enter a code...and remember it because if you forget it you'll lock yourself out.

Then you can set require the password to immediately. You can also lock out installing apps or inapp purchases.