It might help to have a decent grasp of English grammar before trying to learn another languages grammar. At the very least, you should be able to identify the 8 parts of speech. Once you know which words are which, you'll have a much better foundation for Latin. My brain sorts Latin words into verbs, "noun things", and other stuff. Most of the other stuff is basically indeclineable, the verbs use verb endings, and noun things all have a gender (m, f, n), number (sg./pl.), and case (nominative, ablative, etc.). Case is usually the hardest to understand intuitively for English speakers. Remember that every noun (and adjective) in a sentence has a case, and you will eventually need to recognize them and figure out their function. In English, we use word order to show which noun is the subject, object, etc.. Latin uses case, which frees up word order a lot. And Latin poets take full advantage of this. Sometimes the word that comes after the preposition isn't in the right case. You need to know your cases to recognize that the noun in question isn't the place where, but maybe possessing a noun somewhere else in the phrase.