OS X version 10.14 or is required, how can i update

You can get the installers for older version of macOS by using Safari to click the link from this page.

You don't state what Mac you have (model and year) but check the compatibility lists first. It's likely that your Mac could go beyond 10.14

Remember to make a backup.

My iMac is 27" late 2013 with intel processor i7 3,5 Ghz 64 bits, I know It is compatible

I can go beyond Mojave 10.14, but not my software

Which software are you worried about?