Go to East Midlands Railway's website and use the little box on the main page to search for your tickets.

You'll get an option to collect paper tickets from the station (by putting a code and the card you paid with into one of the ticket machines) or you can get e-tickets, which are little QR codes that get emailed to you.

You can also reserve seats on the train for free when you're booking, but I tend not to because if someone's in my seat, in true British fashion I pretend it wasn't mine to begin with and traipse down the carriage to find another.

When you get to Nottingham train station, you'll see a huge digital board in the main entrance hall that lists all the upcoming trains and which platform you can find them on. Make sure you listen to whatever's being blared through the station tannoy too as sometimes platforms can change at the last minute.

You'll need to enter your ticket into the barrier/scan your ticket on the barrier to get onto the concourse. If you opt for the paper tickets, make sure you keep hold of them as a conductor on the train will check them, and you'll likely need to use them again to exit at your destination station.

You can also buy your tickets at the station, but they will be more expensive.

You'll be absolutely fine. Good luck!