Don't sweat it, its easy. I was required to do a written welding theory test, don't remember how many questions. Seemed pretty easy.
I struggled with the metalurgy. I knew this was a weakness of mine and should have prepared more but did okay anyways.
The hands on was easy. Welding a vertical groove on 3/8" plate with backing SMAW, come on it doesn't get much easier. Also 6g Sch.40 pipe with SMAW, 6g with GMAW on Sch.40 pipe. Both 6".
Had to run some aluminum TIG. Also either stainless or mild steel TIG. Had to do some silver brazing. I had never worked with this until two days prior. It was not difficult. Cut coupons and bend from all tests and pass.
Seems like i had to run some FCAW, but i don't remember for sure. It was not on pipe i know. Maybe a plate groove on 3/8"?
I was concerned-too much. I believe i ended up with like 90 or 92 out of 100? I did not feel that confident when completed but professionals are critical of their work.

Take some time to refresh your memory in areas you know are your weaknesses. I hadn't welded with GTAW in ten years, except in the garage on the bike. Just did some touch up and it was fine. Most of this stuff is like riding a bike, you won't forget. But you should check to determine the processes you must run, and touch up on them beforehand. My SMAW tests were perfect. The TIG was good, but a real TIG hand could have done better. The MIG was very good, but could have been better.

They are not expecting you to be an expert at every process involved with welding. This test just verifies that you have experience with these processes and that you are capable of performing acceptable weld profiles with them.

Hope this helps.