Level 2 is done in three, 2 hour sessions, so 6 hours in all on the road, for children and inexperienced adults.
I usually cover this in 1 or 2 sessions for adults and include some level 3.
A memory jog for those of you who have had training and a more complete explanation is here.     Memory Jog Level 2

The High Way Code

Starting and stopping on road

Starting by a parked car

Road  positions

How to pass a parked car or slower moving vehicle

How to pass a side road

How to turn left from a major road into a minor road

How to turn left from a minor road into a major road

How to turn right from a major road into a minor road

How to turn right from a minor road into a major road

This is the basic level 2 and nine year old children usually only do this, but with older children and adults we can go a little further and include some or all of the following.

How to negotiate a narrowing or country lane

How to use mini roundabouts

How to do u-turns