my Mac Book Pro thinks it is up to date. Curently running 10.9.5 want to install High Sierra, cannot find it in app store

Assuming your MBP qualifies...

macOS High Sierra - Technical Specifications

General Requirements

• OS X 10.8 or later
• 2GB of memory
• 14.3GB of available storage to perform upgrade*
• Some features require an Apple ID; terms apply.
• Some features require a compatible Internet service provider; fees may apply.

Mac Hardware Requirements

For details about your Mac model, click the Apple icon at the top left of your screen, choose About This Mac. These Mac models are compatible with macOS High Sierra:

• MacBook (Late 2009 or newer)
• MacBook Pro (Mid 2010 or newer)
• MacBook Air (Late 2010 or newer)
• Mac mini (Mid 2010 or newer)
• iMac (Late 2009 or newer)
• Mac Pro (Mid 2010 or newer)

Don't use Firefox for this link...

https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=12

If you get a corrupted message...

Naw, not damaged, it's just that you have an old copy already in Applications, there are 2 cures...

Disconnect from the Internet & set the Date back to 2014, then you can run the Install MacsOS High Sierra App in Applications, so expired Certificates are not expired.

Or... trash the Install MacsOS High Sierra.app in Applications then a new copy more recent version can be downloaded.

What exact model do you have? Only Macs from 2012 and later can install Catalina. See the following to find out which versions of macOS you can install.

• How to upgrade to macOS Catalina
• How to upgrade to macOS High Sierra
• How to upgrade to macOS Sierra
• How to upgrade to OS X El Capitan

Any luck yet?