As someone with a construction science degree (like Casey) and who has built a dozen decks, this isn't an impossible feat for a skilled homeowner, but based upon your questions and lack of confidence, I would suggest you have it built by a professional.
The contractor needs to verify the structure of your home to determine the best method for attachment, needs to check the span tables for the lumber to ensure it is adequate, and needs to either have a good understanding of the footings required or know someone who does and get their direction. Improper bearing soil or undersized footings could cause the deck to sink or worse
collapse. While this is a possibility of any deck built by a novice, most of the time a 2 foot collapse isn't going to kill someone.
Many people THINK they know how to build a deck, but even after watching a recent DIY show where supposed deck experts competed against one another, 2 out of 3 improperly built the structure.