I would like myself and someone else to sign a document how do i do this?

I would like myself and someone else to sign a document with Adobe DC Pro, how do i do this? I have created an agreement that myself and another person needs to sign. How do i go about acheiving this? If i attempt to sign thee document i am inform by adobe that the document can not be changed after and if i send the document to be signed then i am unable to sign it after the other person has.