Having instructed in both the USA and the UK I would certainly recommend that before you fly in the UK you make yourself familiar with the UK CAA chart and airspace which is very different to the FAA sectional chart. Also different are semi-circular rule, traffic pattern/circuit entry, VFR transponder squawk, information/ radio service instead of Unicom.
It is not that difficult but if you just launch off you might find out the differences the hard way. Plus there are lots of small instructor differences. When I learnt to fly in the UK in a Cessna 150 I was taught not to lower the the flaps in a turn. The American circuits are tighter and FAA instructors have no restrictions on lowering flaps in a turn.