My grandfather is a truck driver, but I didn't know they were called  truckies in Australia and New Zealand.
That sounds like an Australian term!  Truck driving sounds like a tedious and hard job.
Yes it is because they transport finished goods and raw materials over land, typically to and from manufacturing plants, retail and distribution centers.
Do truck drivers get paid well for their profession?
I am pretty sure they do, because they are responsible for inspecting all their vehicles for mechanical items or issues relating to safe operation.
Sounds complicated.  Do truck drivers have to buy and provide their own trucks?
I am not sure,  I just know they are responsible for their vehicles mechanical issues
Do truck drivers have to go to school to be able to drive?
Some may have to to obtain a commercial driver's license (CDL) to operate.