Here is a question concerning the video on the present perfect:
Can I translate the preterit (simple past) instead of the present perfect? For example, “I did my homework” or “I have done my homework”
To answer your question, you can substitute the preterit (simple past) for the present perfect when it is not important to make a link with the present, and this is quite common in American English:
AmE: “did you eat yet?” “avez-vous déjà mangé?”
BrE: “Have you already eaten?” “avez-vous déjà mangé?”
In your example, saying ‘I have done my homework’ suggests that at the present moment the homework is completed, there is no more to be done.
‘I did my homework’ tells me that at some moment in the past the homework was done, but there is no connection with the present: you may have more homework that needs to be done!