That is a super sweet birthday gift!
I sailed out of Chicago Sailing in Belmont harbor for 10 years before relocating to northern Michigan. In addition to renting, CS offers a timeshare type of deal that may be worth considering. There are 2 other companies that do this as well, one is Pinnacle, and I can't recall the other. Pinnacle has nice boats, but I've heard scheduling is tough.
At CS, there are 4 Hunter 326's, one of which is fully loaded for exclusive use of the timeshare deal. It is almost ALWAYS on the dock! However, even if it's being used, you can still hop on the J30's, J22's, or J24.
Owning your own boat is great in a lot of ways, especially if you love to tinker (not like, Love). Also, you can put your own clothes, foulies, tools, etc. on board.
But owning costs way more than renting/timesharing. Insurance, drop in/haul out, storage, maintenance, etc. all adds up.
Since you say that you want to just daysail, this may be you bag. Then you could take the extra cash and bareboat in Door County, Traverse City, Apostle Islands, and/or North Channel!
We've all heard that "if it Floats, Flies, or F*cks; Rent." But, I love my wife and our boat! I just thought you should consider other options. Good luck!
1976 Hallberg Rassy Rasmus 35' Ketch