Following the speech from the Prime Minister on March 23rd, everyone must stay at home to help stop the spread of coronavirus. This includes people of all ages -- even if you do not have any symptoms or other health conditions. You can only leave your home for one of four reasons:
shopping for basic necessities, for example food and medicine, which must be as infrequent as possible
one form of exercise a day, for example a run, walk, or cycle -- alone or with members of your household
any medical need, or to provide care or to help a vulnerable person
travelling to and from work, but only where this absolutely cannot be done from home
These reasons are exceptions -- even when doing these activities, you should be minimising time spent outside of the home and ensuring you are 2 metres apart from anyone outside of your household.