Osquery uses basic SQL commands to leverage a relational data-model to describe a device.

osquery

I want to manage devices, restrict internal employees from using USB storage devices, upgrade the system by myself, etc. I don't know if Fleet can meet these needs.

Hi <@U088MBP7YNR> - Fleet provides device management and allows for self-hosting with admin controlled upgrades

It doesn’t allow restricting use of USB storage but policy management will allow you to report on USB usage 

We have customers that build their own workflows to take policy failures and build connections to their internal access management tools for enforcement  