My two favorite spots are
Soust East
Brands Hatch Race Circuit, Fawkham, Longfield, Kent DA3 8NG
Prices vary from nothing (on some practice days) upwards but never massive amounts.
What will you see. All types of motorsport including bikes, sidecars, cars old and new and trucks.
Indy and Grand prix circuits both offer great opportunities
Information on their website
http://www.brandshatch.co.uk/
Location it is just 3 miles off the M25 jn 3
Lots of facilities, parking and you can take a picnic
No dogs!!!
Season now coming to an end but truck racing and fireworks on this weekend.
There is usually something on most weekends out of the winter months.
London
Bushy Park, Hampton, Middx, TW12 2EJ
Large walled Royal Park of 1100 acres
What will you see. Red and Fallow deer, Grey Heron, lots of assorted ducks, and geese. Dragonflies and other insects. Squirrels, parakeets and loads of other birds. If you are lucky little owls, kestrels and kingfishers. Oh and some big fish in the stream between the two main lakes.
There are also great landscape opportunities with misty mornings and evening sunsets over the various ponds. Also good for candid portraits.
Wooded walks and open space.
Kids can ride bikes and there is a play park.
FREE parking and entry although it does get busy at weekends, check website for opening times as they vary throughout the year.
Website
https://www.royalparks.org.uk/parks/bushy-park
There are a couple of places to buy food and drinks.
Hampton Court Palace and the river Thames are also very close.