Public transportation in the UK is very visitor-friendly. Car rental (hire) can be more expensive in England, and the price of gas (petrol) is significantly higher than in the US. Note that gas prices are listed in litres, not gallons!
England has an extensive overground and underground rail system that doesn’t require reservations. However, if you plan on using the train for personal travel, reserving tickets in advance can save considerably. London features an underground subway system referred to as “The Tube,” and visitor tube passes are available for tourists. Bus services are frequent, and taxis are also available. Children 12 and under ride for free on many public transport services.