After submit form, open blank

Unfortunately it’s not a built-in option to print submissions at this point. There is a third-party add-on that is good for generating and printing PDFs, however:
https://www.formidablepro2pdf.com/

If you have additional questions about this, it would be great if you could post in our help desk:
https://formidableforms.com/help-desk/
We try to keep all support and presale questions in the help desk.

Or can do it only showing his blank after submit. Not print?

It would be best if you post your questions in our help desk:
https://formidableforms.com/help-desk/

We can better assist you there.