The certifications classes are not that beneficial since you are attending college. You could probably get a certification book from a fellow prepharm that is working as a tech or cheap offline.
You can pass the test if you know how to read a prescription, which book/guide is needed to look up specific information, some easy compounding questions, knowing how many pills needed for a script, and brief drug classifications.
I also studied the book prior to the exam and aced it.
Knowing nothing about pharmacy and studying enough to do well on the exam would probably take me 15-20 hours.
I had been a pharm tech for a year, studied the morning of the exam and did really well. I am used to doing this though. I worked two jobs, had heavy science courseloads each semester, performed research, and was a Teaching assistant all through college. GPA 3.32 for 167 credit hours for a biochem chemistry double major in 5 years.