If you want to send and receive files via kachery, you (or your administrator, for shared setups) will need to install and run kachery-daemon on the machine that you intend to be the host of the node. You will also need to use kacheryhub.org to connect your new node to the channel you'd like to use to share data.
Once this is done, install kachery-client and you'll be ready to start!
See sharing data between workstations using Python
The largest use of kachery is as a library to facilitate other applications, such as web applications; see our section on building projects that make use of kachery.