It is unfortunate that Mill Hill in London does not have any chess clubs. The good news is there is Hendon Chess Club not too far away in West Hampstead and Barnet Knights in Hampstead Garden Suburb which is ironically closer to Hendon than Hendon Chess Club is!
I specialise in coaching chess to people up to a rating of roughly 1800. This is important because I will cover positions and aspects of the game that are likely to crop up here and not situations that are fantastically unlikely to occur in this rating range. The latter should be reserved perhaps for a coach who is a grandmaster for a higher rated player and because these strange situations are more likely to occur. For example, a lower rated player is far less likely to encounter an endgame of Knight and Bishop and King versus King.
Please see the link below for my tutoring venues in Mill Hill and Barnet if not possible in your home.