See below for three links to Government advice following The Prime Minister's TV address on Sunday. If all is not clear when you've read this, you won't be alone! Stay safe and stay home as much as possible would still seem to be the best approach.
This is the link to advice on what you can and can't do (but see also later update shown above from 29th May) followed by another link to specific advice on staying safe outside your home and finally Our Plan to Rebuild - The UK Government's Covid-19 Recovery Strategy for those who seek the nitty-gritty.
Happy reading and stay safe and stay well!