I went from knowing practically nothing about AWS to passing the AWS CSA exam in less than six weeks. I went through the AWS Concepts course, the AWS Essentials course and the AWS - CSA course during that time and figured I should try the exam while the concepts were still fresh in my mind.
Here's a couple take-aways I have from the test. First, make sure you understand AWS solutions conceptually. This isn't a test where you can memorize questions/answers. I think this is the biggest reason this course works. I went through a handful of practice tests while preparing and I didn't recognize more than a couple questions on the test itself.
Also, be sure to re-read all the questions. There were quite a few questions where the correct answers were based on a single word or phrase (think block vs. object storage, OLTP vs OLAP, etc).
Finally, be sure to get an understand of the capabilities of Route 53, Kinesis Stream vs. Firehose and EMR. Also, give a browsing through pricing structure for the main services so you have an idea how things are billed.
Thanks LinuxAcademy and spec ifically Thomas Haslett for a great course!