Is there any way to sail the Danube on a budget? [closed]

I'd like to sail down the Danube next summer, on my own, on as small and cheap a vessel as possible (no big motor boat, maybe not even a motor boat at all). I haven't decided on the length of the trip, but would expect a couple of hundred kilometers during a couple of weeks.

Using a raft with no guidance is probably a pipe dream, as I have zero sailing experience and no equipment. (I asked a question over on outdoors.stackexchange.com some time ago.)

Are there any services along the Danube that offer long-term rentals, some amount of training/introduction to navigation basics, equipment like lifejackets, etc., and with whom one could return the boat further downstream?

While seeing the Danube delta would be great, I'm totally open in regards to where to start or end the journey.