User 1 prefills to send, applicant signs, User 1 countersigns using a workflow template

We are trying to find an easy way for our Leasing Specailist at our apartment communities to collect information and get digital signatures on rental applications. We will use workflows and template so everyone has the same paperwork with every transaction.

As the account administrator, how do I set up a the Participant Roles of a template that will become part of a workflow?

Here are the steps that we need to have happen:

1.  I create a workflow (with a template) that will be used by the Leasing Specialists (employees) at our apartment communities.
2. The Leasing Specialists need to prefill information, then send to the Applicant.
3. The Applicant will complete information and sign.
4. The Leasing Specialists will need to countersign.

I have the prefill fields ready. But, how do I assign the Applicant and Countersign fields? As Participant 1 and Participant 2? Or, does the "Countersign" role get added as part of the workflow? Thanks for the help, I can't find this anywhere in the manuals or tutorials.