First, learn, realize and understand what are the endings actually about. That they're the functions indicating noun's (not only) gender, number and case. Compare to English dog-dogs - the "s" here being the word's function for plural. Second, realize that Slavic language's (such as Czech) morphology is rich and that there is PLENTY of the endings and choose an approach to learn them. I discuss them elsewhere, excuse my laziness to just copy-past the discussion: Czech tutor here. There are two ways, generally. ... https://www.reddit.com/r/languagelearning/comments/64jkhr/how_would_you_go_about_learning_cases/

Hello Shawn, Yes, all nouns (and not only) have different suffixes depending on the case you want to use. Books usually introduce cases (and therefore endings) based on the order of how used/useful the particular case is. We usually teach the accusative first - it's the case which comes with verbs like "want" and "like", that is, verbs that you use all the time. Then the locative (connected with prepositions of place) comes. The particular endings you have to memorize. Unfortunately, no one has come with a better way of learning it :) Good luck with your learning!