I am confused about 15A and 20A current.

Electrical Expert:

(1) How do I get 20A out of the main power line in my house?

(2) Is it typically setup 15A ?

(3) Is there a conversion unit (15-20) available?

The reason that I ask is that as soon as I turn on the Rotel RB-1090 (rated 380W) the circuit breaker breaks.
Thanks,

-TT