Wanting to be independent of her abusive alcoholic father a teen takes driving lessons with her pensioner neighbour discovery the father figure she needs and caring really means.

After reading this I realized you don't have an inciting incident. You have situation normal (The abusive father) You have an action (Taking driving lessons)
But you don't have the incident which drives the teen to go from situation normal to the action.

The goal should be extremely hard to accomplish - everything rests on the goal which is the outer journey - without it there is no story. The audience should be clear what this goal is and know exactly the moment it is accomplished, or not. Wanting to be independent, if this indeed is the goal, will not be enough to sustain the audience's interest in a feature length film.

What this logline suggest is the completion of her inner journey i.e. 'caring really means'.

Sounds very low concept and low stakes.
Take Harold and Maude as an example of a similar dynamic (only with the gender reversed), both the teen and the pensioner were, each for their own reasons, emotionally damaged. Their relationship became the saving grace for both of them - they found happiness and a renewed lease on life with each other. The stakes were that this was going to be taken away from them because society frowned on their relationship.

What is the equivalent in this concept? what's the worst that will happen should the teenager not get a drivers license? What's the best that would happen?

If the father is abusive, now day and age with social help, the teen can find a different home to live in or the father will be removed. A licence can hardly substitute the authorities intervention.