No, you can enroll for any learning path/certification by just enrolling into a single course and for remaining courses, you can enroll later whenever you want. Here are the steps to enroll for a learning path/certification by selecting a class for any one of the mandatory courses within:
Steps:
Go to Catalog section in Home Page
Search for the Learning Path / Certification to enroll
Clicking on the Title or More button will take you to the details page of the training
In the details page, it will show the list of available classes under every course
Select your preferred class in any of the courses to enroll
After clicking on ‘Enroll Selected Classes’, you will be successfully enrolled in the learning path/certification