Driving

Driving on the left side of the road is something one gets used to very quickly. The first hour, the brain shoots out some warning signals as it sees cars approaching where it is not used to seeing them. Ignore those, keep the side of the road at your left shoulder, and you’ll be fine.
The steering wheel remains on the “wrong” side though, making left turns difficult if visibility is limited as one sees the opposing traffic later than someone sitting at the right side of the car. The only option is to slow down for such turns.
The only true difficulty in the UK is the many roundabouts with specific lanes depending on what exit you wish to take (turbo roundabouts). The layout is often unforgiving. If one selects the wrong lane, taking the corresponding (wrong) exit and making a short detour is the only option. Use a GPS with good lane guidance to avoid losing too much time doing this.

Food prices

Food is more expensive in the UK due to a variety of reasons, including higher import costs, and generally higher take-home pay.
Also, eating out is considerably more expensive.
If a service charge (tip) is not added to the bill, in many places you will be expected to add one yourself in one of the following ways:

• Some card payment terminals have buttons where you can choose (10%, 12.5%, …).
• Ask to round up to a figure of your choosing before paying.
• Leave a tip in cash.
  Typical tipping rate is 10% or 12.5%.

Petrol

At many petrol stations, one can simply take the petrol first, then go inside and pay. Outside card payment terminals are regularly not available.
Service stations exist but are generally a bit removed from the motorway. Look for signs mentioning “Services” and follow the directions.

Parking

Outside parking

Often the procedure is to park your car, go to the payment terminal, and enter the license plate to pay. Instructions should be available close to the payment terminal. In some cases one is expected to leave the paid ticket behind the windscreen. On CCTV-equipped parking lots, this might not even be required.

Underground parking

This can be somewhat more tricky depending on the system that is used:

• CCTV: if your license plate is recognized as “valid”, the barrier will open automatically. To pay the bill, before leaving the parking lot by car, type the number of the license plate on the payment terminal. Note that the British CCTV systems often struggle with non-British plates but still somehow interpret them as “valid” and open the gate. This is for instance the case with plates starting with a number, which might be automatically removed by the system as British plates never have this structure. Hence, if you cannot find your license plate when attempting to pay, remove the leading numbers or try different variations of the plate.
• Ticket: If the license plate is not recognized, or CCTV is not available, take a ticket and pay at the machine with the ticket before leaving the parking lot by car.