Welcome and congratulations on your new to you Mini Lite. WRT the tires, that depends on what shape they are in. Given that they could be original you should check closely for dry rot and wear patterns. Any concerns would cause me to change them. New tires are less expensive than the damage that could be done when tires explode at highway speeds.
I don’t know about the TV, but if you have both a 12 volt and 110 volt plug the choice is yours.
Check Amazon for “RV side mount table” and you will see some brackets, tables and grills.
2021 Rockwood Mini Lite 2205S
2011 Ford F-250 Super Duty 6.7L Diesel