How much is a train from Newbury park to Staines?

Staines is not in the London travel zones - which only go up to 6. You won't find a through fare from Newbury Park either, as that is a tube station only and does not come up on the usual train fare sites like Network Rail and the trainline. Your best bet is to use your Oyster Card to travel to Waterloo, then get a ticket to Staines.