Hi Danielle,
For a great overview of the process, refer to this document in the SAP Cloud for Customer Administrator Guide
You'll find each migration template within the solution and on the migration activity related to each particular object.
For example, under Business Configuration > Implementation Projects > [select your project] > Open Activity List.
Then select the All tab and search for All Activites and enter the search term: migration.
Choose the one you're interested in and then choose the link to Migrate [xx] using the migration tool.
Once the migration tool opens, you can upload source files, download the template, etc.
Cheers,
Angela