Congrats on the job!!! Do not let your sweetness be your downfall let it be your incredible strength. When "oerdering" people around, simply use your sweet way about you. With the jerks, have a fun tone about you and don't stick around for the argument back. Say your peace and be on your way...you have too much to do to be diplomatic.
A front office position can be very deceiving. It does look like a calm and quiet job of answering phones and doing paperwork but it is the "front lines". Any job where you are the beginning of the transaction and the end (not to mention the in between) is a terrific opportunity to show skill and time management but yes can be very time consuming and hectic. Find a rhythm. Take charge of your day with a secret list...one that you make and keep daily of how your day will go and what order it will be. It will help you stay in control and understanding that it will be interrupted by walk in appointments and client calls, will help you to show yourself and if necessary, your managers that you were diligent in completing your tasks. (not to show them but if they ask how you manage you can let them know of your secret list of things to accomplish for the day).
Small displays of self management show as self confidence and will allow for some consideration when they question your work ethic. If they see you taking control, smiling your sweet smile and delegating tasks along with keeping things tidy and staying on top of this, they will not micro manage you and you will be very empowered.
Best of luck to you and these kind of jobs can be very secure and know one thing, within the industry of collision work and such, if you make a name for yourself , others will want to hire you as well...you will be a hot commodity.
I work in the insurance industry and have close relationships with several shops. I enjoy dealing with tightly run and reputable businesses and certainly appreciate a smiling voice and diligent front office person to handle my clients. :)