First, you should drop the "the" before 23rd. Second, you need to capitalize "Ridge".
With those corrections in mind, The first is correct in AmE; the second is correct in BrE.
For your last question, both "on" and "at" are correct and have the same meaning.
I will meet you at the corner of 53rd and Broadway.
I will meet you on the corner of 53rd and Broadway.