A landed on my leg while my knee was straight and my knee hurt and the next day hurt but no swelling could i have torn my acl it was like a 1foot fall?

Possible: Landing from a height puts excess stress through the knee. It could be as straight forward as a knee sprain or contusion but could also include ligament, meniscus or even fracture.

ACL less likely: With a low energy extended/straight knee injury, it is more likely you sustained a mild knee strain, meniscal tear, and/or a ligament sprain (mcl common, especially if tender over mcl). Without a significant acute effusion, an acute acl injury is less likely. A simple instability exam by your pcp or orthopaedic surgeon will confirm the diagnosis. See md if pain > 10 days.