Just show the Thai Immigration Officer a printed copy of the DTV visa you have received. IF any questions, give the initial booking address of your hotel or place you will be staying. No need for ADDED bookings...just say if asked that you will be searching available hotels or condos.
You may have to show PROOF of your DTV Visa to airline staff on check-in for your flight ✈️ to Thailand...even to the connecting airline staff. Or to the land border crossing entry Thai Immigration Officer.
Upon arrival into Thailand, show the DTV visa to the Thai Immigration Officer and look at the STAMP placed in your passport to be sure you are STAMPED in for 180 days.