They have different meanings, but in fact the message is the same.
1. 'I got some fruit for you' means, for example, I went to the shop and 'I bought some fruit for you'. This is the past simple, used to talk about something that you did in the past.
2. 'I've got some fruit for you' means 'I have some fruit for you' now. It looks like a present perfect form, but it refers to the present time.
Sometimes people say 'I got' to mean 'I have' but this is colloquial/incorrect English eg 'I got a problem'. You shouldn't use this form if you want to be taken seriously.