Employee center latest version update

Hi All,

I have a basic query related to Employee Center update.

We have configured and customized few parts of employee center already. 

We are migrated from Service Portal to Employee center, and configured to access Employee center with /sp URL.

Now I see some capabilities/options are missing in Employee center and I realized we are still with the version 25.0.5

But I see the latest version available in store as 28.0.4 and we are in Tokyo.

I want to update to latest version of employee center.

So want to know is there anything that I need to be aware of before update or after update to make sure my current configurations and customizations are not affected?

I'm new to ServiceNow and Employee Center. So kindly suggest.

Thanks,

Sagar