If you have the user rights that allow you to delete REDCap, then you'll be able to delete individual files and records as needed.
Deleting a Whole Record
As a fist step, go to the record status dashboard to see your data.
Then click on the record you would like to delete.
Select Choose Action, and then Select, "delete record"
Deleting a Form in REDCap
As a fist step, go to the record status dashboard to see your data.
Then click on the form you would like to delete.
At the end of the form you can select "delete data for this form only"