When you build a new Timeline using our Wizard, You picked a template as the first step. However, you can change and/or Add to additional template to the timeline you are using by selecting a new one, and clicking on 'Install Template'.
You can also Import a shared template here by clicking on Import Template.
Do be aware, when you opt to install a template, you are presented with the option to Overwrite the actions in the current timeline, or add to those. Overwriting, will remove any actions that are pre-existing in your Timeline. Adding will add the additional actions that are contained within the new template that you are installing or importing.