Traveling to any foreign country has its requirements; however, the UK is on the stricter side, so read this guide to avoid being denied boarding.
To avoid any embarrassment at the airport, check your passport is still valid and that it also has enough time left before it expires.
Transport for London still asks all passengers to wear a face mask if they are visiting London.
Although this is changing all the time, your travel provider should be able to advise you on the latest information before your flight.
A visa can be a typical entry and exit requirement in most countries. The excellent news is that you may not need one visiting the UK.