If you have a Wal Mart or Camping World near you, check prices. Usually dealer's prices are higher.
All are do-it-yourself items. Items 1 & 2 are not needed right away but they are nice to have.
Usually, the dealer gives you a cheap, thin sewer hose which isn't worth a darn. Go to WalMart or Camping World and purchase the heaviest-duty one you can find. It's worth it. Then you can see about the adapters, etc. that fit that particular hose.
WalMart also has the white RV water hoses.
Toilet Chemicals? Definitely not needed. All you need is an extra bowl of water to flush solids. Water is your black tank friend. We've never used chemicals - a waste of money.
Good luck with your purchase.