As explained here on what templates are and how to add templates. We will create multiple projects/engagements using an already created templates. To achieve this, on the Engagement page, click on the Add Engagement button, on page load, you will be asked to choose the Engagement type and choose from already created templates, and click on the Go button, on page load, you will be asked to confirm engagement details and key deliverables before using the apply button, after confirmation, please click on the Apply template.