If you showed up with the starter kit that sysrq linked to with hammer, level and markers (Go to an office supply store and buy a large box of sharpies keep them in your car) I would say you are ready for the work I would have a new hire doing.
You can build from there, a lot also will depend on the type of work you will be doing.
Wiring wood frame houses will use a different set of tools then wiring a concrete and steel building.
If you end up doing service calls you need different tools for that.
I am predominately a service guy as such I use a fairly small tool bag as you will always fill it to the brim and it becomes to heavy to carry. In the truck I keep a wide selection of tools that move in and out of my bag as I need them.
Welcome to the forum and the trade it is a good one.
Bob