You can easily add new components anywhere you like to an already installed template.

There are three ways you can do so –
1. Use the Create a Row button:
After every component, a small green button  appears at the bottom. Click on this to add pro components just below.

2. Add from the Component List:
Click on Components  icon present at the bottom-right corner of the editor page.This opens the list of all the components available. Drag and drop row component, divide them into columns and add whatever components you require from all the kinds of available components.

3. Duplicate Component:
You can also duplicate some components and use it in your site. Open the Action Bar of the component that you want to duplicate and click on Duplicate  icon.

The duplicated component will be placed just below the original component.