Little Chef when i left school, waitering, cooking etc. They offered me a trainee managers job, i refused, i had no direction as a school leaver. Perhaps things would have been different if i had the foresight, perhaps worse.
At 17, worked for a US/Canadian seismographic surveying company looking for the Vale of Belvior coalfields. Awesome job, 17, driving a 3.5ltr landrover across country and generally having the time of my life and earning twice my peers wages.
At 18, various jobs in the building trade, general labour usually.
At 19, engineering storeman which developed over the years to an engineering administrator/buyer. Had that one for 23 years, excellent job, mediocre pay.
Change of job completely and went on the tools at circa 42, maintenance engineer in the citrus packing industry. That took me to Cyprus many many times, Uruguay, Spain and Egypt. Good job, good money for an unqualified man on the tools.
That lasted 10 years, then to my current employer, same job, same industry...less pay. But ok pay...meh, it is what it is.