Don't bother with London info on a short flight like this - it could take most of the time to get a word in and there's not much they can do for you.
Ferrybridge through to Coal Aston talk to Leeds. Tell them you are a student pilot on a navex and request a basic service. Thus you will have highly trained ATC with radar instantly available regardless of whether you are in their airspace or not. Amazingly they will keep an eye on you as they fully understand what "student pilot" means.
Then talk to Doncaster as you have planned. Use plain English (if the RT words escape you for a moment) and make sure to tell them if your route enters their airspace.
Main thing is not to allow the radio to distract you from the nav and look out.
Have a great trip and let us know how it went.