United Kingdom uses 230V, 50Hz with socket and plug Type G.
United Kingdom sockets/plugs are completely different than in France so you will need an adapter. You can buy one from Amazon which supports wide variety of sockets/plugs, not just the ones for United Kingdom.
Frequency is the same in France and United Kingdom (50 Hz) so there shouldn't be any problems.
United Kingdom also uses 230V as France so you don't need a converter/transformer to convert a voltage as it's the same.