Hi Bert,
Yes, a comma is correct after the expletive.
No, there is no comma after your "And" because we do not separate the second sentence from its coordinating conjunction unless there is an interpolated clause.
And, if you're curious, this sentence is an example of the above.
Finally, remember that punctuation is not grammar, the first being visual and the second being audible.
https://tinyurl.com/t8b55upp