The hours depends on when you solo.
Before you solo you have to learn how to hover.
Some people never solo. I have seen guys fly 60 hours of dual and they can't even hover, so they call it quits.
Use a flight instructor who has soloed other folks. The mistake I made was using a new CFI and he had not soloed anyone. He was way too catious and we racked up the hours. I new I was ready at hour 25 but he wasn't.
After solo you need a few hours of local solo to include some short solo X-C flights, night dual and at least 3 hours of dual test prep.
FW to heli is smiliar except for quick-stops and autorotations.
And never take your hands off the controls.
It should be fun and hopefully you will have the time of your life learning to fly helicopters, I did!!!!
PS- I did do an addon.