Start with Creating an Org before starting on Trailheads
Creating a form using OmniScript elements, following the design shown in the attachment
Create a DRE to Retrieve/Extract Contact details from Salesforce.
Create a DRL to Insert/Update Contact details to Salesforce.
Create an Integration Procedure to use as data source to FlexCard
Create a FlexCard to display Contact details
Create a new Community site in the org