It probably depends.
You say you have no background in anatomy. If your educational or professional background in some area that is related to fitness? Are you a long term fitness enthusiast (as the phrase goes) who has a strong background int he application of exercise technique? What made you decide to do the training?
When I took by PT certification years ago I had already worked in fitness for a long time, had a group ex certification, and spent about a year preparing. I also took college level classes in exercise science. I don’t train outside of my own specialty anymore, because I know just how much work it would be to jump back fully into that world.
I think one thing you might want to do is to call them and tell them what your background is and ask them that question. They should be able to give you clear guidance based on knowing what is in their material. You will also want to ask whether the exam is practical as well as written, and how long the exam takes.
Another thing to do is to preorder the study materials and start to read them before you book your workshop. This will give you a better idea of the scope of the material. Some people find memorizing bones and muscles and so on hard, but even if it is relatively easy for you it does take some time if you haven’t spent a lot of time on it. And that is just the surface of what a good certification exam would cover.
Keep in mind that if you were hiring a massage therapist you would not want someone who had spent 3 days learning how to massage and then put up their ad… you would certainly want your carpenter, or the person who is putting in your gas lines to have done more than 3 days….. I bet you would even want the person who cuts your hair to have the best possible training and experience. So the more you prepare for this not only the better will you do with the workshop the better you will do, the more prepared you will be, and the more professionally respected when you step out into the work force and start working with people.
So I would say prepare as much as you can. Read, study, do flash cards, buy a copy of the Anatomy Coloring Book, practice with different equipment if you are able to do so safely, …. and enjoy the workshop. The worst thing that would happen is that you would feel that you were not yet ready for the test, and then you could study some more. Taking the workshop will be a great way to learn.