How exciting! We have a little spaniel and she's just the best thing we ever did!
I'd highly recommend pawesome for dog walking.
https://www.pawesome.co.uk/
We use Mike as we live near Wandsworth Common, but the company are extremely professional, reliable and just love dogs! We have met a few of the different walkers over the years we have been using them and they are all great!
Trainers... I'd recommend Winkie Spiers.... she is so practical and helpful and always put the dogs needs first..
Good luck!