Hi,
Let's look at 'remember' as an example.
Simple Past - Last Wednesday, I couldn't find my car keys. But the next day, I remembered where I put them.
Present Perfect - I have remembered where I put my car keys. Now we can go for a drive!
In my earlier post, I just tried to give you the general idea of these two tenses. There is much more detail about the various meanings and ways to use the Present Perfect. I suggest that you look at these in your grammar book. You can also find lots of interesting discussions if you search this forum for 'Present Perfect'.
Best wishes, Clive