Good for you for trying softfoot13!
For me, thinking of starting at almost 37 years of age PT with the "hopes of being full time driver in 3 years" at age 40, would give me some "SERIOUS" pause to what I was getting into.
Maybe knowing when I can retire maybe one of the right question's to ask. Knowing what my chances are in being able to make it on to the drivers list then become a driver would have been high on my list, let alone how physical and mental the job is, would be my priority question.
Then again I don't know Shift!
I myself could have never done this job starting at the age of 37. Altho I saw a few get hired and try their hand at a driver position in their early 30's. I would say from my experience maybe, just maybe 10% were able to so.