In the case of GP surgeries closing due to Coronavirus or short staffing, NHS out of hours advice still stands. This can be found here: https://www.nhs.uk/using-the-nhs/nhs-services/urgent-and-emergency-care/nhs-out-of-hours-services/
Information on support from your pharmacy can be found here: https://www.nhs.uk/using-the-nhs/nhs-services/pharmacies/
Hospitals are cancelling non-essential appointments, and publishing their own guidance on Coronavirus on their websites. Check before travelling.
You can find a list of NHS Trusts linking to websites here: https://www.nhs.uk/servicedirectories/pages/nhstrustlisting.aspx
You can find a list of Clinical Commissioning Groups linking to websites here: https://www.nhs.uk/servicedirectories/pages/ccglisting.aspx
General NHS information on Coronavirus can be found here: https://www.nhs.uk/conditions/coronavirus-covid-19/
NHS England has put out the following comprehensive guidance to the Heads of Clinical Commissioning Groups and NHS Trusts across the country, determining which services should continue to run, which should run with limited capacity, and which will need to be discontinued during the outbreak: https://www.england.nhs.uk/coronavirus/wp-content/uploads/sites/52/2020/03/COVID-19-prioritisation-within-community-health-services-with-annex_19-March-2020.pdf