Legal Question in Product Liability in Illinois

I'm slightly confused by your question. Do you want to represent yourself pro se and file an appearance as such? Or do you want to retain an attorney and have him/her file an appearance on your behalf?

Either way, you file an appearance in the court where you are summoned. Assuming you were sued in state court here in Cook County, you should go to the 6-8 floors of the Daley Center and stand in the right line (the staff can direct you). It is generally about ~$200 to file an appearance and you should probably do so before your court date.

Disclaimer: I am not your attorney and this advice is only generally applicable and may not apply to your case.