Hi. We have a day trip planned for London coming up, 2 adults and 3 kids. What is the best way to get around? Would prefer to avoid the tubes if we can (not a fan). Would like to go to Kensington, then probably Covent Garden/Leicester Square area. I know we can probably walk a fair bit of it. Getting the bus, do we just buy a ticket when we get on, as we do up north , or can we buy some kind of travel card? Thanks, and apologies if asking stupid question