18, just like it is in the whole of the United States.
In order to obtain a CDL permit, you have to pass a driving test and get your license. When you get your license for a CDL permit, then you will be ble to drive trailer trucks and/or buses whenever you want to.
Your CDL permit is in addition to the class of licence you had beforehand. So long as you were licenced to drive a car before you got your CDL permit, you can drive your own car while you possess a CDL permit.
What type of permit? A CDL permit is, yes. A regular learner's permit is not. As with a full CDL, you're required to maintain a current DOT medical card with a CDL permit.
No, it does not. Anything on your MVR prior to you getting a CDL will still be on your MVR after you get a CDL.
Yes. Aside from the CDL permit, it's a regular license.
It's illegal to drive alone on a learner's permit at any age in any state. The only exception to this is for persons who have a CDL learner's permit - since they must already possess a regular license prior to getting a CDL, the CDL learner's permit serves as a regular license and a learner's permit for CMVs.
Only if you're insured on that vehicle. Only those insuring driving schools are going to insure a CDL permit driver.
Sure you can - but not as a CDL driver.
You can obtain a CDL at the age of 18. However, you would be restricted to operating a commercial vehicle only within the boundaries of your home state (the state of issue), and you could not obtain an endorsement to haul hazardous materials. You must be 21 to do interstate transport in a CMV, and to obtain your hazmat endorsement
People will not be able to locate the answers to the Ca CDL permit test online. They will have to study the manual to know the answers.
You're going to have to pay for the permit... no two ways about it. If you take the written tests, the only thing you'll have to pay for until you get an actual CDL is the permit itself, and you can take those tests at the DMV - you don't have to go to a truck driving school for that.
As much as your state charges... CDL requirements are federally regulated, but prices are not. All you have to do to upgrade to an "A" permit is take the combination vehicles written test and pay the fee.