When a family sends you an agreement, My agreement under My paperwork shows it on real paper, page by page. Read it, type your full name (and your credential or title when the signature block asks for one), tick that you have read it and that you agree to do business electronically, and tap Sign. The family signs next, and you get an email when it is signed by both. If something is wrong, Decline and leave a note; the family can send a new version. Print or save as PDF keeps the signed copy with its certificate of completion as the last page.
If you joined through the Marketplace, your Provider Home shows Your agreement with ExpressAgain: Agreement 5, the Professional Marketplace Participation Agreement. Read it, sign with your name and credential, and ExpressAgain's block is countersigned automatically at once.