As of May 2020, there are 59 courses operating in the United Kingdom.
17 of those are dual-purpose – Flat and National Hunt.
Racing can be accessible to all, however for some of the flagship meetings, you are looking at fairly entrance fees. For the Cheltenham Festival, for the cheapest enclosure – £35.00-40.00 up to £85.00-100.00 per day. The Epsom Derby is even more expensive.
Like anything the standard of service and facilities vary greatly, like the standard of horses racing.
Generally speaking the peak of the flat season in Great Britain is between May and September. For National Hunt it is November to March.
Horse racing in the UK is governed by the British Horseracing Authority: https://www.britishhorseracing.com/