how can I update my Mac Pro to latest version ?

If you are referring to an iMac Pro (at the bottom of your post), it can be upgraded to the current macOS Sonoma. See the following from Identify your iMac model - Apple Support

iMac Pro

Model Identifier: iMacPro1,1

Part Numbers: MQ2Y2xx/A, MHLV3xx/A

Newest compatible operating system: macOS Sonoma

To upgrade to Sonoma, see: How to upgrade to macOS Sonoma - Apple Support

Be aware that if you upgrade to Catalina 10.15 or later you will also need to update any non-Apple 32-bit apps. See: https://www.stclairsoft.com/Go64/

or

 https://www.macworld.com/article/232735/how-to-check-if-mac-software-is-32-or-64-bit.html

what model-year Mac Pro desktop or MacBook Pro notebook and screen-size?

 Menu > about this Mac.... but please don't post your serial number, it attracts vermin.