Hi Sheena!
Thank you for bringing your question to the Disney Parks Moms Panel!
I'm sorry you have found some confusing information. Because
Walt Disney World policies tend to change over the years, information on the internet is often outdated. I think this has an added layer of confusion because the policy isn't completely clear as stated on the water park websites. The website simply states that there is a $2 rental fee for towels. However, it has been my experience in the past, as well as other Moms Panelists' experiences in the very recent past that Walt Disney World Resort Guests are given complimentary towels. The Cast Member will generally ask to scan your MagicBand. I would guess that this will be your experience. However, different Cast Members may have different information, so if you definitely want to avoid the $2 rental fee, you can always bring them from home.
Both
Disney's Blizzard Beach and
Typhoon Lagoon do offer complimentary life jacket rentals. Simply ask a Cast Member to point you in the direction of the rental location and you will leave a refundable deposit. Since it is possible for them to run out of jackets, I recommend that you go there immediately upon arrival to get the sizes you need.
I hope this helps! Please let me know if you have any other questions.