Hello, welcome aboard!
The good news is that you can have water, black coffee and any sort of tea (without milk). Until very recently we were only allowed to drink leaf teas (mint, nettle, green tea, black tea, etc) but recently they changed the rules and you can drink any sort of herbal tea, including fruit teas. So do some experimenting and see what you like - there should be something out there to tickle your tastebuds. Even better, the liquid in your tea and coffee counts towards your water intake.
Now, the next bit's controversial but this is the 100% forum, so I'll give the advice that diet coke, coke zero and Pepsi max are all off limits. People will tell you otherwise and that they "get away with" downing the odd can but strictly speaking, it's not in the rules. People will tell you all sorts of things about it being because of citric acid content in Diet Coke and Pepsi Max interfering with ketosis (there's phosphoric acid in Coke Zero so folks will say that's better) but actually one of the key reasons is that the artificial sweeteners in cans of diet pop can trigger off food cravings. Best to avoid as far as possible. And that's lots easier now that all the different teas are allowed.
Finally, after a couple of weeks you'll be able to buy the artificial water flavourings from your CWPC - Summer Berry and Sunshine Orange - to add a bit of taste to your pints of water.
Hope that helps!
