Super sorry it took so long to reply. I’m not on often enough on my computer to sit down and right a helpful response. So I’m sure you already figured out an answer :) or maybe not. Verbs are the most difficult grammar concept in any language.
Whenever it comes to grammar, online my favorite resource is Tae Kim’s guide.
Transitive verbs (even in English) take a direct object. The verb cannot happen without a noun object related to it. Intransitive verbs do not take a direct objet. Intransitive means they can stand alone. (INdependent / INtransitive). If it makes it easier, forget the words transitive and intransitive and just focus on their functions. Because honestly, every time I practice/learn new verbs I have to look up with the word transitive or intransitive means first, and that just gets in the way. Learn how to use them.
Honestly when it comes to verbs I learned how to use them through time with practice. There is sort of a rhythm to verbs that take an object and those that don’t. Verbs that take an object (あける、しめる、つける) often have an え sound as the last letter of the verb stem whereas verbs that don’t take an object usually don’t (あく、しまる、つく)
Of course that’s not a rule and definitely not an all the time thing, but often times that is the case for the verb structure between the two types of verbs.
In Japanese を is the direct object particle. It goes between the verb and the object(noun) it’s being attached to. が is used for relating an intransitive verb to a noun.
Looking at just the definitions of these verbs may make it difficult to tell what the sentences are actually saying. Let’s use the example on the guide I linked above.
“The ball dropped" vs “I dropped the ball”
「ボールが落ちた」 vs 「ボールを落とした」
In the first sentence, the verb does not take a direct object. You could put 落ちた in a sentence by itself. Of course, out of context, it might not make a lot of sense. But it is, indeed, a sentence. In this sentence, the focus is on the ball.
In the second sentence, the verb 落とす takes a direct object using the particle を. You can not use 落とした as a standalone sentence. Think of saying “I dropped” in English. Okay, what did you drop? It needs a direct object. In this case, it’s the ball.
In Japanese, the subject is marked by は or が right? And in this sentence there is no defined subject. Because unlike English, if the subject is obvious (in this case “I”, it can be removed). 私はボールを落とした is the full sentence. The focus is on you, the speaker and not the ball.
I know this is a lot to take in. Verbs are intense. I still don’t have a perfect grasp on them. Definitely read that article for more tips and explanation.