Well I'll be the first one to give you generic information that you could have found with the search function.
You just do the needful.
Good screwdriver set.
A network tone tester in case you need to map out your network and document everything. Also functions as a basic cable tester.
A punch down tool.
An ethernet crimper.
A quick cable stripper.
A usb hard drive dock.
Your necessities may vary, this applies to more of a one-man shop, and there's plenty of other things you'll want to get that I don't have listed here depending on your job.
I dunno how much you should get paid.
There's no such thing as an "ESXi book" any more than there is a book about the windows calculator. It's a fairly small part of the vmware vsphere environment.
You can start with this platform independent book:
Thomas Limoncelli's book is pretty highly regarded: https://toptalkedbooks.com/amzn/0321492668
I personally created this Poster a while back... feel free to use it: https://www.reddit.com/r/computertechs/comments/1qhcsa/poster_troubleshooting_in_black_and_white/