Welcome to CockersOnline, Jane. I am just down the road from you, in Leicestershire and I have a 9 month old black cocker spaniel bitch, called Tilly. Charlie sounds a handsome lad! Tilly is a dainty girl and weighs just 20 lbs, but as she plays with lots of bigger dogs, I think she thinks she is a Great Dane.
Good luck with the walking. I found that stopping in my tracks when Tilly pulled and getting her to come back to heel worked well for us. She soon got bored and realised that pulling on her lead resulted in us going nowhere. She is pretty good now, and only forgets herself when she sees another dog in the distance. I never let her pull me along anywhere - but as she is only little, she can't budge me and this isn't difficult! I am sure you will crack it with time and patience.
Have fun at classes - they're the highlight of Tilly's week. She is in an all-cocker class, so we spend a lot of time laughing at their funny antics!
Sue