Congratulations on your decision to seek certification for yourself! It really depends on the individual. I know that many recommend a six month study period but one could have years of experience, and cram to refresh those areas maybe not as often utilized, and pass. When I joined IAAP, I had several people tell me to sit for the CAP right away because "you will surely pass" but I had younger children at home, and a full-time job, and did not want to risk failure because I am pretty hard on myself when I do. So, I waited and the right time came for me and I passed. So, consider where you are on time, find peace, then set your date to sit and start studying.
Linda R. Perry, CAP, OM, PM, TA, Notary