Hi Nick,
Welcome to the forum and to XT ownership!
After many years riding bikes most of us take for granted changing chain and sprockets.
However, I remember well my first bike whilst living in '80's London bedsit land with no tools, garage or mates with bikes. It took ages for me to build a reasonable set of tools.
Have a good read of the service manual and you will soon find that general maintenance is pretty straightfoward - just make sure you always use the right tool for the job and don't rush it.
Good luck and enjoy!
Rick