No one can say for sure what your sentence will be.
730 ILCS 5/5-8-1(a)(7) provides that the term of prison for a Class 4 felony is generally between one and three years. 730 ILCS 5/5-9-1(a)(1) says that law provides for fines of up to $25,000 for felonies (corporations may be fined up to $50,000.)
Some offenders receive suspended prison sentences and avoid actual prison sentences through completion of terms of probation.
It all depends on the extent of your criminal background. A class 4 felony is the lowest level felony in Illinois. A class 4 felony does not carry a mandatory minimum prison sentence. It is a probationable offense and unless you have an extensive criminal record, I would assume you will receive probation. Although you can be fined up to $25,000, I would expect a much lower fine. Most criminal judges do not issue high fines on cases like this. Most judges will order you to pay court costs (usually a few hundred dollars) and a small fine. Good luck to you.
Class 4 felonies generally carry a maximum $25,000 in fines plus costs and 1-3 years in prison. In most cases, probation and other alternatives to prison are available. Rather than start with the question of how you'll be sentenced, start from the perspective of retaining the best possible criminal defense attorney you can find who is familiar with the Court where your case will be heard so that you have a chance of fighting. Good luck.