I have been searching for the differences between these two tenses. I thought I finally understand them but when I watch a movie, the usage of simple past tense is different than I expected. Most of the time, past simple is used without a time expression. I thought that present perfect should be used if time is not given. (unless you are telling a story about the past) For example in this video: https://www.youtube.com/watch?v=GzFWI8KvGmE&ab_channel=linguaclips I would use present perfect instead of simple past. For example: (Instead of saying Where did everyone go? I would say Where has everyone gone? because there is nobody at home)
The usage of the present perfect in English is one of the subtlest points in English usage.
Time markers usually suggest using the past rather than the present perfect. Here is a counter example
"I have seen him, just yesterday in fact."
Here the present perfect is giving emphasis.
Recency usually suggests present perfect, and lack of relative recency usually suggests the past, regardless of time markers.
"Julius Caesar has invaded England" has no time marker, but an event some 2100 years in the past requires the past tense.
The fact is that the distinction between the two tenses is very hard to reduce to simple rules.