According to current national restrictions in England, you may not meet people indoors, unless you live with them, or they are part of your support bubble. Outdoors, you can only meet one person from another household. You should not leave your home, unless you are attending work (where you cannot work from home), or performing an essential activity - like shopping for food/ medicine, for exercise, education or childcare, or for a medical reason.
More information on existing measures is available here.