I solo'd on a tailfragger at age 16. One with a near 50ft wingspan to boot...
I went on to become an instructor on said aircraft and taught plenty of youngsters who were able to solo safely in under 10 hours.
The aircraft was of course the Vigilant TMk1 Grob 109b belonging to the RAF operated by the Air Cadet movement.
For conversion purposes for a low time PPL I would say 3 - 5 hrs dual with an instructor would be fine. Make sure you get you logbook signed for the legal aspect re. "differences training".
What I would say is that you should only operate the aircraft with lower limits than you might in your Cessna. Until you have 50+hrs on taildraggers I would limit myself to 10kts Crosswind, 20kts Total wind and operating from tarmac at least 15m wide.
Enjoy your flying. Tailwheel aircraft are excellent primary trainers which demand and embue a greater "finesse" in their pilots.
Cheers,
WWW