I spent about 7 weeks in the Springs area this past Fall. I didn't make reservations and just went by whatever campgrounds were with Passport America and then stayed as many days as they could fit me in. It wasn't the best way to go about it, but I had no definite plans so I had to be flexible.
Foot of the Rockies is a decent park and the spaces are large. It's nothing fancy, even though it's called a "resort." No restrooms, pool, or anything other than free wifi and a laundry room. They have a nice view of Pikes Peak and Garden of the Gods, but you have to strain your neck to see it sometimes.
Goldfield RV park is not too bad either. My first impression was negative but then it grew on me. It's a glorified parking lot but the spaces vary depending on the area of the park you're in. They have free wifi, I think cable tv (I don't have a tv so I don't make note of those things), a laundry room, bath house, and it's in Old Colorado City.
There's another one in that same area but just down the street. They aren't with Passport America and they aren't the cheapest but they are pretty decent. There is a brook that runs along it. Fountain Creek, I think is the name. They sell propane (just an FYI for when you're in the Springs and are looking to fill up.)
I spent time in Walmart parking lots in between the campgrounds and I can tell you that they are growing less and less hospitable because of the problem with the homeless there. People living in their cars and leaving piles of garbage in their wake when they drive out of the parking lots. It's sad and they are ruining it for people who are more conscientious about how they leave their imprint.
It's a very busy time to be in that area so if you can make a reservation, you might be much better off. I wish I could give you a glowing report on one of the campgrounds I spent time in but they aren't anything to crow about.
Enjoy your trip! So much to see and do there and Fall is so lovely.