By law, the learner driver should have the provisional driving
licence and learn from a certified driving instructor (be it school
or private).
And then, he should only learn at stipulated locations, such as
within school's circuits or designated roads, AND at designated
times.
Peak hours cannot have driving lessons on the road, etc.
The car's ownership may be less important, but basically, the
act would have endangered people's lives! Remember that at
carparks, there are many people & children walking, also
there could be many cars driving in & out, so its more
dangerous.
Person A is 100% going to get his PDL revoked and ban from
learning driving for up to 2 years or more. While Person B
will get his license suspended for 1 year or more.
Depending on whether Person B has any driving instructor license
and on the timings of the act, what stage Person A's driving skills
are at, the driving conditions/no. of people in the carpark, &
if Person B collect fees from Person A, the Judge will met out the
punishments accordingly.