You do have the right to represent yourself, however, the expungement statute needs to be read & followed carefully. As previously stated, you are only permitted to expunge your cases one time in your lifetime with limited exceptions. If you proceed on your own, be mindful that you may not get a second chance if you get it wrong.
You can always represent yourself in court. You can find articles online that discuss Indiana's expungement statute.
HOWEVER, the Indiana expungement statute is rather confusing, and you only get ONE chance to file a petition IN YOUR LIFETIME. If you screw it up, you're out of luck. Yes, it will cost money, but your best bet is to get an attorney to represent you.