If you have never changed a flat tyre before, it is much easier than you think. There are loads of useful videos on YouTube for changing a tyre so check them out...
https://www.youtube.com/watch?v=ntYIITLp90k
Top Tip! Try removing an inner tube from your wheel before you have to do it for real in the comfort of your own home or garage. You don't want to be trying it out for the first time when it is cold and wet!
Or you just need to take a Simon with you on each ride!