I have a Coursera Plus subscription so I can't really check, but usually you can "audit" the individual courses for free, but you won't have access to the quizzes or a certificate.
https://www.coursera.org/learn/microsoft-azure-cloud-services?specialization=microsoft-azure-fundamentals-az-900
That's the first course, if you log in to Coursera and then click on "Enroll", there should be an "audit" button at the bottom.
A handful of courses have auditing disabled though.
Also, there's the option of starting the 7-day trial and cancelling it before you get charged. Kinda a jerk thing to do, but I guess you could rush through the graded quizzes and get the certificates within those 7 days for free.