I upgraded to the Personal Plus and the GCP playground is mostly useless for the first several labs. I can’t do anything with Billing, can’t create a project due to lack of permissions, the cloud shell terminal editor will not work…who knows what else. I wait to see what others say but I think it’s best to cancel membership and go with the free option.
I never upgraded and I found that just using my free trial google cloud account worked really well through the labs for me. If you run out of free trial credit (which is incredibly unlikely in this course), you should be able to create a new google account with a new billing account and give your user account access to that billing account for another free trial credit if needed.