There are many online services & desktop software applications available to measure usage of internet or bandwidth.
To connect two computers without using any hub or switch, you need a cross-over cable.
What is crossover cable?
How to setup a LAN (Local Area Network)?
LAN Network setup and internet connection sharing.
Learn Networking with only one computer!
Do you want to learn yourself networking?
How to learn networking without many computers?
Is it possible to learn Server & client operating systems without having more than one computers?
Yes, it is possible.
With virtual networking you can do it.