How can I fix my leaning garage wall

The gable wall in my garage is leaning. The sill plate seems to have slipped off the foundation. The sill plate is broken and the lower end of a stud is missing around where it’s broken.

The foundation is not totally crumbling but I’m not sure if it’s solid enough to slide the wall back on top of it.

Do I jack up the wall, push it and anchor it back to the concrete?

I can sister the broken stud. What about the sill plate?

Should I replace the whole plate, or can I just reinforce that section?

Could this damage be caused by settling, Or did someone drive their car into the wall?