Best way to learn

Hello,i recently had a job where id have to do demos, consultations and implementations of halopsa,as i know nothing about the product,i started a course and my success has proven to be less than ideal, reading and memorizing doesnt seem to be the best way to learn this product,what was your go to learning method and do you have any tips or advice to help me?wether its practical advice or mental advice im all ears.