The penalty for driving without a license as an underage minor will diff from state to state depending upon state laws that are in place. In many states not only you as an underage driver will be cited but the owner of the car that allowed you to operate it while unlicensed could also be ticketed and penalized.
Driving without a license is also a considered a serious offense in most states. The penalties again differ by state laws but can include things such as fines, jail time and vehicle impoundment.
These types of violations as a minor may allow your state's licensing department to delay your driver's license application from going through once you do apply. Also these offenses will likely go on your driving record. Even being a minor without a license does not stop your state from starting a driving history to record these offenses.
For example in Connecticut according to their laws (CSG 14-36h and PA 05-215) the penalties for operating a vehicle without a license, violating the driving requirements for 16 and 17 year olds, driving when under 16 or violating other licensing provisions vary depending upon if it is your first offense or not.
CT laws state that a first time offense comes with a fine of $75 to $90. Subsequent convictions for this offense can come with penalties that can include up to 30 days in prison and a fine of $250 to $350. This section on Connecticut law also notes that if a person was previously convicted of violating these provisions they can be fined an additional $500 or up to 100 community service hours. Also if 2 previous violations have occurred there will be an additional mandatory 90 days imprisonment.
In some states you will get the prescribed penalty, fine, etc for driving without a license plus an additional monetary amount due to the state. In some states it is called a surcharge while in others it is termed a driver responsibility assessment. For example driving without a license comes with a $100 surcharge in Texas.
Even if you are a teenager with a learner's permit you can get cited for driving without a license if you operate a vehicle against your restrictions. For example Delaware law states that persons who violate the Level One Learner's Permit restrictions are considered as driving without a license which will result in a 2-month suspension for the first offense and a 4-month suspension for subsequent offenses.
It appears you may be in the state of Florida. According to Florida laws a person may not drive any motor vehicle upon the roadways in this state unless such person has a valid driver's license. This Florida law concerning this is under 322.03 of the FL state statutes.
Driving without a license can result in fines and/or jail time. Part 6 of statute 322.34 notes that any person who operates a motor vehicle without having a driver's license is guilty of a felony of the third degree. The penalty for a felony of the third degree is either a term of imprisonment not exceeding 5 years and/or $5,000.
Other Florida statutes may also apply such as FL Statute 322.35 which is titled Permitting unauthorized minor to drive. Here it states that no person shall cause or knowingly permit his or her child or ward under the age of 18 years to drive a motor vehicle upon any highway when such minor is not authorized by the provisions of this chapter. The FL driver's manual notes that you can be put in jail or made to pay a fine for allowing an unlicensed person to use your car.
So as you can see if as a minor you are caught driving without a license the person who let you drive their vehicle may also get in trouble depending upon state laws. In many states it is unlawful for any person to cause or knowingly permit any minor under the age of 18 years to drive a motor vehicle upon a highway as an operator, unless the minor has first obtained a license to so drive a motor vehicle.
It appears that in FL that both the unlicensed minor and the licensed driver who allows the person that does not yet hold a learner's permit can both face penalties including fines and jail time. If you were cited for these actions in FL or elsewhere, find out for certain what your penalties are by contacting the court listed on your ticket and/or your state's Department of Motor Vehicles.