Hello Joker ,
The difference between present perfect and simple past is as follows:
The past simple tense describes an action that took place in the past and is terminated now .
For example " I gave up smoking several years ago" means I don't smoke at all right now and the action of smoking terminated in the past .

The present perfect tense describes an action that started in the past and is terminated in the near present or just right now when the sentence is said. For example "I don't know where she is ,have you seen her ?" Here he is asking if the other have seen her in the past , probably the near past and he could have just seen her nearly before the sentence was said, so the action extends to the near past and terminates JUST there .

- Did you buy your house ? ( Asking if the house is already bought and the action of buying is terminated in the past )
- Did you feed the cat ? Yes she fed it before lunch. ( The action of feeding the act is a past action " before lunch" )
- Where have you been ? I have been out . ( The action of being out started in the past and extended to the near present ,where the question was asked, the guy was probably coming home in ,when he was asked by someone "parent, spouse etc" .
- Did you enjoy it ? Yes very much .We took part in a race .
Did you win ? No we came in last .
( Here the actions are all past, they all terminated in the past ,the enjoyment , taking part in the race ,winning , coming last all are actions that terminated at the moment when this dialogue is being held.
I hope the idea is clear now :)