Learners mix up the present perfect and the simple past not because the forms are hard, but because both of them talk about the past. The difference comes down to a single question: is the stretch of time you are describing closed, or is it still open?
Compare two sentences. I lived in Bandung puts that period firmly behind you; you were there once, and you are not there now. I have lived in Bandung leaves the frame open, suggesting either that you are still there or that the experience still counts as part of your life up to today. The forms are almost identical, but they say different things.
This is why time markers so often make the choice for you. Yesterday, last year, in 2019 and two hours ago close the frame, so the sentence needs the simple past. Ever, never, just, already, yet and so far keep it open, and they pair with the present perfect.
The most common mistake grows straight out of that. I have finished the report yesterday sounds reasonable in your head, but yesterday has already closed the frame, so the sentence has to be I finished the report yesterday. Keep the present perfect for sentences that do not name the moment, such as I have finished the report, where the point is the result you are holding now.
When you hesitate mid-conversation, ask yourself one thing: am I saying when it happened? If you are, use the simple past. If what you mean is the experience itself, or a result that still stands today, the present perfect is the one you want.