RE: So, there's not a sprinkler head. Just 2 PVC pipes with end caps
Your filter should be with the valve so at pvc pipe time it is typically plug and play. It's just about getting the part to connect to the pvc pipes which used to be in any hardware store, at least where I grew up
Edit: Ask a guy at your hardware store where the part is and he should be able to help you find it. Even if you don't know what it is called, if you can describe what it does, that usually will work. "It hooks my drip system up to the pvc pipe. You know... that thingy. The hook up thingy. It does that."