It's unlikely that you will be able to visit if your conviction is recent...
Locate the state, then the city or county where you think they are being held.
If you have a criminal record, specifically if you have been convicted of a felony in the previous three years, you will usually not be allowed to visit an inmate.
If you are on probation or parole, it is unlikely your visits will be approved, however check with your jail or prison for their guidelines on this issue.
To find out how to visit someone you know, begin your search for an inmate or arrestee here:
To find your jail or prison visitation policies, begin by finding the facility or prison system here: