Concerning California law:
Yes.
http://dmv.ca.gov/dl/dl_info.htm#two500
you have to hold your learners permit for 2 years now before you can get your license. regardless of how old you are.
My son recently just received his learners permit. He needs to hold on to it for a year before he is able to get his license.
At 18+ you do not need to take the learners class [drivers ed] you can directly take the test for getting your license.
Any new prospective driver, regardless of age, is going to require a learners permit and gain driving experience with a licensed driver before they are eligible for their "solo" drivers license.
This completely depends on which country/state you live in. In the UK, for example you have to be 17 before you can get your drivers license whilst in North Dakota you can get a drivers license at 14.
30 days
You will have to be in drivers ed for approximately 6 months before you can get a drivers license.
6 months
There is no required no. of hours. the permit is good for 6 mos. and you can take the drive test whenever you feel like you are ready.
it takes on year
If you relocate to a different state you will have to get a new learners permit. However, if you relocate within the same state you do not need a new learners permit.
If you have never had a license before anywhere, the answer is YES, in Georgia, you must get a leaner's permit before you are first licensed.