Amazon will sell you an “RTIC” 36oz 24-hour water bottle for $23.

For the dutch oven, x2 on the TJMaxx/HomeGoods/Marshalls idea. But if you can’t find one there, a “Lodge Logic” (the “Logic” bit just means pre-seasoned) from Wal-Mart will do fine. They are cheap, and will last long enough, even with constant use, to be dug up by archaeologists in a couple millennia.