There are various clubs, associations and charities that can help those walking for a hobby, social activity or even fund raising events.
NHS Choices has a walking for health section which offers advice on starting out walking and staying motivated, as well as the recommended physical activity levels for your age group. Join the friendly, beginner level health walks in your local area with trained walk leaders.
Living Streets is the UK charity for everyday walking. Their campaigns include the walking month of May and Walk to School Week to encourage walking as a daily activity. Living Streets also sticks up for pedestrian needs with campaigns such as preventing parking on footpaths.