My GOD they're making them enormous these days! Don't they know there's a fuel shortage on?
Eeh. I'm kind of a fan of the vertical wind tunnel, and kind of wish I'd spent about half an hour in there prior to my AFF 1 jump. Other folks here complain it's not really anything like skydiving, but I think learning what the wind feels like and getting to where you're reasonably stable on your belly might free up more brain cells for other things. Things like paying attention to your altimeter. Or maybe it won't. This is also a great sport for shattering expectations.
You're a few pounds heavier than I was when I started. If that affects your fall rate like it did mine, I'd suggest making damn sure you're altitude aware and pull when you're supposed to. My instructors were terrified they might not be able to catch me if I got away from them and didn't deploy when I was supposed to. One of them later called me "The fastest falling, most altitude aware student I've ever seen." So if you fall fast, also be altitude aware! Actually, be altitude aware anyway.
Don't forget to breathe on your first AFF jump. I think I did my first three without breathing. From like, the moment I got on the plane. Though not breathing sometimes seems like it has some advantages...
I am preparing to get my A-License this spring here in Chicago. I am 6'9" 250lbs.
Call the area DZs first, and tell them about your height/weight. Even if you can get in under the weight restriction, they might not have a harness long enough to fit your torso. If you do find a DZ that thinks they can take you, I would highly suggest a visit to the DZ well before you plan to start jumping so you can try on the rig they think will fit you. The reason being that if the rig does not fit, there are alternatives, but none of them are 'quick' or 'easy' (and probably not cheap).
If a DZ will let you jump, that's one thing, and having a rig for you is another. If you come up short on finding one with a rig for you, come back to DZ.com and post that you need a rig for AFF. There are some 'bigger' jumpers out there who may have an extra rig they can rent you for your training, or some other similar solution.
If it does come to that, double check with the DZ that they will let you do AFF if you provide a suitable rig, meaning one with the proper TSO (certification) and an AAD, RSL, and big enough canopies to be 'appropriate' for your weight. Typically DZs do not allow students to bring their own equipment, but remind them of your special circumstances, and they might reconsider.
Speaking of the TSO, those are the specifications the rig is built under, and there are different levels. Some of them cut off at 250lbs (or less) and a few go above. DZs may tell you you're too heavy to jump based on the TSO on their student gear, but if you could provide your own rig with the higher TSO, they might reconsider. So for that reason, if you do end up having to source your own rig, you might want to try calling all the DZs again based on the new circumstance.
Yoru last option will be to travel for training. There are DZs in the US who can train you and supply a rig. Again, if you come up short in Chicago, post again and you'll get some options as to where you can go and get your license. Once you have a license and your own rig, you can jump anywhere you want, regardless of your size.