The usages of verb tenses are big topics in language learning, with many pages of explanations and exercises devoted to them in course books. In my opinion, there is no short-cut or easy option - you need to study course books, alone or with a teacher. There are some overlaps with Italian tenses. The usage of the past perfect is quite similar to the trapassata prossimo. However, Italians use it more often than we use the past perfect. For most students, it takes quite a long time to understand and feel well the usages of the present perfect. You have to study and practise them.

This is a very rough guide, but imperfetto is similar to past continuous, trapassato prossimo is similar to past perfect, and passato prossimo is similar to simple past. Of course, we don't have remoto in English. You can start with that, write some texts, and get corrections. When the imperfetto doesn't translate exactly, there's usually another English grammar rule. For example, we have a rule for stative and dynamic verbs in English. Also, in some cases, we use "would" when we translate imperfetto. Your best option is what Michael has suggested: tackle these tenses with a proper course book, or with a teacher. The good news is, these verb forms rely on each other to function properly, so it will help a lot to understand how they work together.

This is far too general a question, Claudia. We cannot give you a satisfactory answer to this enormous question in the tiny space we have on this page! Why don't you find some specific examples of sentences that are confusing you?