Hi Tonia and welcome. I've had my ileo for 27 years since I was 10 years old due to UC, and haven't regretted it once. It gave me my life back!
Before surgery, your surgeon will put you in touch with a stoma nurse who will watch you sitting, standing, walking, etc and mark an appropriate place for your stoma. Please do not let them give you a stoma on or above your belt line since this causes problems with the flow into the bag. If there's time, ask them if you can have a sample of a bag and wear it before surgery so you can find an appropriate site for it.
After surgery, you'll be given a bland diet but after you've healed, you'll be able to add more foods, one at a time, to it. People react differently to different foods so just because one person can't eat a certain food, eg peanuts or corn, doesn't mean you can't. You have to experiment.
You'll be sent home with some bags plus instructions on where to purchase more when you need them. Everyone's skin type is different so what suits one person may not suit another. Again, it's a matter of experimentation with all the different brands out there and manufacturers are more than willing to send out free samples of their products when asked.
At first, you'll probably be living in sweat pants and tops because tighter clothes will irritate your incision. Once you've healed tho, you can wear anything you want... well, almost anything, bikinis might be out (altho I do know some ostomates who can still wear bikinis). Low cut jeans might be a bit of a problem too depending on where your ostomy is placed.
No one can see your bag through your clothes. You'll be aware of it at first and think they can but they really can't. Did you know Bob Hope and John Wayne both had ostomies? The Queen Mum had a colostomy for almost 30 years before she died. The bottom line (pardon the pun) is that no one need know about your ostomy unless you tell them.
Hope this helps.
I'm not a complete idiot - some parts are missing!