For what it's worth, I sail and the average other sailboat I meet is sailed solo by an older guy. A small to medium coastal cruiser/overnighter type seems to be the sweet spot, can be easier to single-hand than many kinds of dinghy, cheaper and with easier boat handling than big cruisers and less to go wrong. So it may not be Atlantic crossing but I hope you get some sailing in.

Illinois boarders a small inland sea named "Lake Michigan" (58000 km^2) that is great for sailing and often has regattas.