Page layout assignment and running post install scripts:

Salesforce CPQ provides inbuilt page layout and fields configured with the following object:

1. CPQ Account Layout

2. CPQ Opportunity Layout

3. CPQ Product Layout

4. CPQ Contract Layout

CPQ Account Layout:

Navigation: Setup | Build | Customize | Account | Page Layouts

        Select Page layout assignment

        Edit assignment 

        Select CPQ Account Layout.

CPQ Opportunity Layout:

Navigation: Setup | Build | Customize | Opportunity | Page Layouts

        Select Page layout assignment

        Edit assignment

        Select CPQ Opportunity Layout.

CPQ Product Layout:

Navigation: Setup | Build | Customize | Product | Page Layouts

        Select Page layout assignment

        Edit assignment

        Select CPQ Product Layout.

CPQ Contract Layout:

Navigation: Setup | Build | Customize | Contract | Page Layouts

        Select Page layout assignment

        Edit assignment

        Select CPQ Contract Layout.

Execute the Script:

Navigate: Build| Installed Packages| Salesforce CPQ| Configure| Additional Settings

                Click on execute scripts button