What to know if this is a serious problem my car has before a mechanic makes it into something big?

I have a Buick lacrosse 2007 and I was backing up one day and made a mistake and hit the lower back end of my vehicle. I went out to check and everything was fine except this thing above the license plate that was hanging out. To be more specific, there is this space above the license plate and this kind of tube thing with some attached was kind of knocked from its original place. Now to clarify there is no hole from the damage that it is hanging from. This is a preexisting space that is perfectly normal with any car specs I presume. My question is: IS THIS SOMETHING I CAN FIX ON MY OWN AND IF SO HOW. IF NOT HOW MUCH WOULD A MECHANIC CHARGE BECAUSE I HAVE NEVER MET A HONEST MECHANIC YET IN THIS AREA (Nashville,TN) AND THAT IS NO OFFENSE TO MECHANICS JUST HAVE NOT HAD THE FORTUNATE PLEASURE TO MEET ONE HERE YET. PLEASE SOMEONE HELP ME. THANK YOU