Hi Ethan
This depends entirely on which temperature sensor you have bought. Do you have the model? If it's a TMP36 (say) googling "TMP36 Arduino tutorial" will more often than not find you a step-by-step guide. If you don't find it that way, find a datasheet for the model you have and you might find it's a drop-in replacement for another component where you'll find a guide.
Alternatively, you'll find a lot of history with sensing temperature in the playground on this site, and in this forum.
Cheers ! Geoff