Hi there and welcome! If you want, you can post pictures of your new find in a thread here: https://www.backyardchickens.com/f/15/what-breed-or-gender-is-this and maybe the members here can help you confirm your suspicion about the breed. Your mention of finding it in "a car park" tells me you are probably not from the states (or at least not originally) - if you go to the https://www.backyardchickens.com/f/26/where-am-i-where-are-you section you can find other BYCers who are from the same place to network with -- participate all over, of course, but just a quick easy way to find folks if/when you have more local questions, looking for new birds, need to sell/give-away birds, etc.
Glad to have you join the flock!
Go to the section of the forums in which you wish to start that thread - say here: https://www.backyardchickens.com/f/15/what-breed-or-gender-is-this - and then click "Start a New Thread" - if viewing the section you'll find it at the top of the page and also at the bottom if you scroll all the way to the bottom of the list of posts for that section. If you are viewing a thread you will find the same "Start a New Thread" at the bottom of the page next to the "Post a Reply" button right below the last post on that page of the thread