These are some other things that I've come across over the years that have significantly improved how I troubleshoot, diagnose, or just found handy to have.
OBDLink Bluetooth OBD Scanners
If you're looking for a great OBD Scanner, there's no better option than the OBDLink Scanners.
OBDLink LX - A great option for Android device users, who just want basic code scanning & clearing. (Amazon Canada)
OBDLink MX+ - This is the top tier option. More vehicle options, Windows, Android & iOS Compatible. Works with FORScan, GM-LAN & AlfaOBD. (Amazon Canada)
If the OBDLink options are out of your price range, the VGate might be something to look at.
VLinker FS - Windows, Android & iOS Compatible. Works with FORScan. (Amazon Canada)
VLinker MS - Supports 5 extra CAN Protocols. Windows, Android & iOS Compatible. 24v System compatible. (Amazon Canada)
Wi-Fi Mesh System
Getting Wi-Fi into the garage can be a pain. If you get spotty reception, I recommend looking into an eero Mesh system. This will help extend your Wi-Fi signal better and further than your main router ever could.
eero 6+ Mesh System (Amazon Canada)
Safety Glasses
I shouldn't need to explain to you why safety glasses are important. So just buy em.
12-pack Sattron Tinted Glasses (Amazon Canada)
Floor Jack & Jack Stands
I will stand by VEVOR products until the day I die. They are cost effective, good quality, and they seem to make something for every industry.
VEVOR 3 ton/6600lbs Air Jack - Lifts up to 17" within 3-5 seconds. (Amazon Canada)
VEVOR 3 ton/6600lbs 10-16" Jack Stands. (Amazon Canada)
VEVOR 6 ton/13000lbs 14-23" Jack Stands. (Amazon Canada)
Creeper
Getting under a vehicle is a pain. Moving while already under that vehicle is worse. Get a creeper, and make life easy.
VEVOR Foldable Z 36" Creeper (Amazon Canada)
VEVOR Dogbone Style 40" Creeper (Amazon Canada)
VEVOR Dogbone style 40" Creeper w/Flashlight (Amazon Canada)