At first level, you would usually have only one encounter spell. Can you, as a sorcerer, have your "Dragonbreath" spell in addition to another encounter spell?
Racial powers are in addition to class powers
Dragon Breath is a racial power granted to Dragonborn. The relevant rule for Racial Traits appears on page 32 of the fourth edition Player’s Handbook (emphasis mine):
Racial Power: Several races give you access to a racial power, which is an extra power you gain at 1st level in addition to the powers your class gives you.
So you get this power as well as the usual 1st level allotment of two at-will powers, an encounter power, and a daily power (plus any additional class feature powers, if a class has them; sorcerers do not).
(Later rules added an alternative racial power for Dragonborn, which you could take instead of Dragon Breath. But it works the same in terms of how many powers you choose.)