[quote=Silver Carrot]
Ooh!...I have absolutely no idea where to start. Bear with me, this is my first nation RP.
[/quote]

It's not that difficult. First, you'll need to think of a name for your nation, what kind of people live in it (race and stuff) and what government it has. 
Something like this:

Nation name: The kingdom of Silver Carrot
Race: The kingdom is inhabited by 8.000.000 anthropomorphic Silver Carrots.
Government: It's a kingdom, King Silver rules his subjects by birthright from his orange carrot throne.
Religion: Carrotfari, The Silver Carrots worship the walking Carrot Monster who's more orange then you 

Basicly, I always start of in general lines. Get like the basics done and then flesh out the details. I might write down that the worship a certain god and later write out the mythology.

Same I do for population. Basicly I choose a race and fill in it's culture later.