Install last CU for SP2 without installing SP1 in sql server
You can just install SP2 and then CU10. No need to install CU for SP1.

You can have a list of all SP + CU here

More relevant info :

If you have a large estate that needs to be patched, you can use dbatools - Update-DbaInstance

Also, dbatools has a really nice - build reference page  that will tell you what the latest SP/CU is and End of support dates as well.