Brian,
I know Steve will get to you when he has a chance, but the recommended order to take the writtens is:
However, it is totally up to you on how you want to accomplish them. Typically, each written builds on itself, the PAR is a foundation for the CAX. The IRA and FII is a similar test bank. The FIA is a build on of CAX. You must pass each written with a 70% or better to pass, wanting to strive for the best result you can get. 3 90’s or better and I’d take the actual exam.
For the PAR, there are numerous apps like ASA Study or Sporty’s Study Buddy App, which all work well, given you follow the recommendation method of studying. Rote memorization will head you well going into the actual test, and you will build the actual knowledge in the ground school portion. Plus, you’ll see key points and it’ll grasp your attention better when emphasized.
Brady