When i started there were no sets and bought as you needed stuff , now roll cabs can come complete with tools.
I liked my toolbox to have music playing and had a car radio ,aerial and speakers and a battery to charge to keep radio playing.
4 lever cantilever to a 6 cantilever and there to Hazet lift tray and added 2 more trays and extensions to give me space.
There are always people upgrading toolboxes and old ones going cheap.
Moving and transporting around or stuck in one place and on wheels saves your back.
I can agree wait until you know what your working on and if using ring spanners never pull it towards you as self smacking comes to mind.
When you fill an engine up with oil its NOT to the brim but a set amount of CORRECT oil for that car.
Latex or non latex to keep hands cleaner and warmer is handy.