We have a park in our yard. Lowes has a set you can buy for around 400 bucks that comes with everything you need.
it can be added onto as you see fit. My advice is don't use the tarp for the roof because the wind will shred it. We put a wooden roof on it and its fine. Just be mindful of hornets that like to build their nests in it.
Go to Lowes.com and see if anything suits you.
