On the Peer-to-Peer Module >Campaign Pages you can choose between creating a brand new campaign by clicking on "+New" and then "Campaign." Or you can select an existing campaign by clicking on the row and make a copy of it by clicking on the "Actions" and "Copy Campaign."

See instructions and examples for creating the campaign in these videos: 

Peer to Peer Fundraising - https://vimeo.com/197190005 (Password: DV2017)

Peer to Peer Event - https://vimeo.com/763864527 (Password: DV2017)