You can check your dictionary for the meaning of "give" and "allow", but there are a few important things to know:
1. "two minutes" here means "a short time" - not exactly two minutes.
2. The sentence with "allow me" is more polite than "give me" in this example.
3. "allow me for two minutes" implies you will be doing something that the other person is already trying.
4. the emphasis on "allow me" is strong: "al-low ME"
Example in context:
"I can't get this computer to turn on."
"Allow me for two minutes"
(three minutes later) "Did you get it to work?"
"No, I'm sorry. You'll need to have someone take a look at it properly."
For more on topics like this, you can sign up for informal speaking practice with me.