What vegetables can I start growing NOW in end of July/August?

I know it’s late in the year to start growing most vegetables, but I wanted to know if there was anything that I could start growing now?

I’d really like to grow potatoes, can I do that? And if so, can I just put a potato in the ground or do I have to wait until it starts to grow roots?

What else can I grow? I’d be growing in those large pot things rather than in the actual ground itself.

Thanks for any help you can give me!
I live in Yorkshire, England