I cannot find a reset button anywhere under my dash board.

Your switch is located under the dashboard towards the right hand side of the drivers side of the dash. Press and hold it for three seconds, making sure the warning light in the instrument panel flashes once every two seconds. if that doesnt cure it than the shop you took it to could have damaged your tire pressure sensors while changing the tires if done improperly.

My tire pressure light was on as well, & no issue with my tires. Turns out it was for the spare, which never crossed my mind.

Under the dash on the right, close to the plastic/firewall junction I beleive.

check the spare, if not, completely empty all 5,. and refill them, (resets the sensor manually)

How to I work the controls on the steering wheel to control my radio/Bluetooth?

On my 2006 Toyota Highlander the reset button was on the LEFT side of the steering wheel under the dash.