We haven't learned the arteries and veins yet.... but you know the femur and you know the femoral nerve serves the anterior thigh so you can guess the location of the femoral artery... yup, anterior thigh. Specifically, it branches from the iliac artery which comes off the abdominal aorta. The femoral artery is one of our largest conduit arteries with very high pressure and it supplies the lower extremity... so it carries lots of blood. Injury to the femoral artery is life threatening as evidenced by the shooting death of Taylor. You might not think that injury to the thigh would be deadly but there is the danger of severing this artery resulting in rapid and severe blood loss... enough to decrease systemic blood pressure which reduces blood supply to vital organs like the heart and brain. In fact, injuries to the thigh are a major concern for combat troops and so companies have designed and tested Kevlar shorts to protect the thigh and femoral artery as well as other important tissues of the groin! Check out this article on kevlar shorts... aptly titled "Saving ryan's privates."
PS - I am not a trauma or first aid expert but if you or your pal's femoral artery is shot, stabbed or bitten (yes, sharks!)... apply direct pressure with a dressing using your hand or even fingers to stop the bleeding... worst case scenario you might need a tourniquet. BUT injuries in the groin or axillary regions might be too proximal to allow proper placement of an emergency tourniquet. In such cases the military is using special clotting bandages that can act to stop severe arterial bleeding (hemorrhaging) very quickly without use of a tourniquet. Check out the HemCon website and QuikClot website as well as this CNN video.