Just assign the source record to the target record. Use the standard assignment element, with a variable of type record for the object. Eg sourceRecord (var type record, using CustomObject(your name) and targetRecord with same var type/object.
Left hand side of assignment has the targetRecord, assignment operation is "equals", right hand side is source record.
Tip1: when enter variable names, remove the period at end of the autofill as do not need the fields, just the whole object.
Tip2: everything is copied/cloned as is (a complete replica for all fields including lookups), including standard fields created date, created by, last modified date, last modified by fields from the source record. You will need to update these field values in a following assignment, eg set created date and last modified date to $Flow.CurrentDate.