Buy good books on the certification for your desired computer career.
Real life has even more detail.
A teacher is not going to talk that much without wearing out their throat, so in the final analysis you are going to spend a lot of time reading and studying those books anyway. A training school recruiter told me that the recommended process for most beginners was to take a class for 3 full days, then study for a month, then take the certification exam. So, that s at least ten days of study in front of a thick book for each day of class anyway. So you re going to buy and study thick books anyway. People can and do pass the certifications simply by studying on their own.