US Immigration from Peru

Is the K1 Visa an immigrant or Nonimmigrant visa? They say differently everywhere you look and it's driving me nuts. Make up your mind people! Haha, but seriously. Anybody know? Also, we filled out the DS-160, for a nonimmigrant, so now we are a bit confused. And they say to pay the fees and fill out the other forms, but where are they? When I go to CEAC, it just says to fill out the DS-160. Our case was approved by the USCIS on March 26th, and we had to call the NVC to get the case number and invoice, we never received the welcome letter which I'm assuming is cause the embassy is still closed. Peru embassy, anyone know when that might open?