I have a "Delta" tub spout that drips. I tighted the screw on the cap and that did not slow the problem. Should I take off the escutcheon plate next?

First shut off the main supply. Remove the escutcheon plate and you should see a screw holding the handle. Remove the screw and handle. You should see a nut like object around the valve stem, remove the valve. If the value uses rubber washers just replace the washer and re-seat the valve if you have a re-seating tool. Most valves are just deisgned to be replace so take it to Home Depot or Lowe's.