Regardless of whether you train in a helicopter or airplane, in order to earn you Private Pilot certificate you will need to:
For the exact details, please consult the Federal Aviation Regulations (FARs) part 61, subpart C and E (especially 61.107 and 61.109).
The training is typically done in three phases:
Phase I - Pre-Solo
Phase II - Cross-country training and solo
Phase III - Checkride preparation, solo cross country, and practical test
A phase is complete when you meet all of the requirements of that phase (knowledge, flight training, experience, proficiency), your instructor endorses your logbook as appropriate, and you pass all tasks associated with that phase (known as a phase check).
Note that these are minimum requirements, which were establihed in the early 1950s, when the airspace and avionics were less complex and air traffic less crowded. Those numbers may not be realistic for most student pilots. A more reasonable expectation is in the area of 70 to 90 hours, with a high variance, depending on the frequency of training, location, age and abilities of the student.
Each student has their own rate of progress, their interests, their own individual ways to assimilate new information. My task as an instructor is to provide a safe and positive environment which allows the student to develop their skills at a pace they are comfortable.