How to retrieve and pass user input data

Hi Nikola,

I am new to WP. I try to retrieve the input information of the user like Name, email and Phone and pass it to other forms and “echo” but I am unable to do that. I was trying to use the “add_filter” and $_POST method but I think I did not use the right hook or code. Would you please suggest me, how can I get it?

Thank you !