LHS to Cottswolds

LHS is what?

Do you mean LHR? (London Heathrow?)

Generally you catch a train into one terminal in London and out of another.

There are some exceptions.
For Canterbury you are looking at St Pancras or Waterloo.
If you are renting and dropping off a car in the same location, you might want to consider somewhere with a direct connection to a London terminal. Stratford involves changing.
Most towns have car rental outlets.

If you want to rent a car, why not just do it at Heathrow and return to Heathrow then take train to Canterbury? Piccadilly Line to Kings Cross then train to Canterbury.

Could just rent out of Heathrow. How tough is it to get in and out of there? That’s why I thought maybe to get out of the area might be a good idea. I need to keep looking for direct connections…Thx

You might look for car rentals in Reading or Oxford.

Getting out the Heathrow; the central area has a one way system but it is well sign posted and you’d want to aim for the M4 either to go east towards central London and to go west, which is the way you’d go for the M25 which goes around London. If the rental depot is out of the central area then it’s probably a bit easier to get to the Motorway (= highway in the UK)

If you can get Google maps (or similar) on the phone in the Uk and expand the scale it will help get you towards being in the right lane at the right time. If you’re unfamiliar with driving on the left, having another adult in the passenger seat keeping a watch on traffic and signs won’t probably help, at least to start.

Sorry for the wrong acronym… Thank you for the replies as well-much appreciated.. All good ideas. Steve