Besides the automation, you also have the option of finding contacts manually.
In Step 2 - Opportunities, click on the opportunity you want to find contacts for.
Use the Search by domain mode to reveal all employees associated with a company, or search by job title.
To find contacts by name, click over to the Search by name tab and type in their full name - and job title, if needed.
Additionally, you may use the manual email finder/verifier in the Toolbox tab on the left-hand menu.