I have just started learning Django and my main aim is to build a company intranet website where I can do system administration things like backups, restore, etc.
I have found various Django tutorials about general web sites, but I could not find any tutorials / links where some have thought about doing system administration things via a web interface.
How can I use models / views and integrate with Python functions?
If all you want is to do administration tasks then I suggest using webmin. If you just want to do this to learn Django/Python then feel free to use the functionality of webmin as a guide. Think about all the steps involved in taking backups, moving files around and other administration tasks. This should help you understand the problem better and break it into manageable chunks.
Remember that Django is really just Python underneath, and it can be a vastly powerful tool. Try looking at some of your Python scripts that you use for systems administration. Maybe you can adapt those as a web interface.