paulvb, if at all possible, leave your girlfriend at home, or ask her to come over for a week or so outside your flying schedule. I don't know exactly what sort of course you are going to do, but in any case a three-week PPL is very intensive, and I suspect the other flying courses are too. You'll have to get up at 6 am-ish to take advantage of the weather, prepare, fly and evaluate two (sometimes three) flights a day so you will only be back 6 pm-ish or maybe even later. Then a bite at the winghouse or one of the other local establishments, grab a beer and back in bed by 10 pm-ish. Or earlier. At least, that's what I did for three weeks straight.
Unless your girlfriend doesn't mind not seeing you and is able to take a lot of initiatives on her own, she's not going to enjoy it.
Do as one of the students did during the period I was there. He took a full week off flying, moved into a hotel, got his girlfriend over, saw the sights and generally had a good time. He took her back to the airport for her to fly home (I think he actually got an instructor with him and dropped her off himself at Orlando International...), then moved into the student housing again and went on flying where he left off.
There are private houses/apartments in the Kissimmee area which you can rent if you want to for shorter or longer periods, but OFT doesn't arrange this for you, as far as I know. They only offer you the shared apartments or the Best Western. So you'll have to make arrangements yourself. And you probably will have to get a car, since there's not a lot of houses/apartments in general, within easy walking distance from OFT.
And I have to concur with bladewashout, some of the younger students, typically the ones that are on the Cabair integrated, commercial track, doing their PPL at OFT, need a little babysitting. I don't mind if they make a mess of their own room, but they also make a mess of the public areas, and then leave the place without cleaning up. Me and a fellow housemate (the only two occupants at that time) spent an evening hauling trash (mostly empty plastic bags and leftover, non-perishable food but some perishable and stinking stuff too) out of the apartment. The cleaning lady only cleans whatever she can get to...