I have a vericose vein on my left leg on the calf muscle can this cause leg & knee pain?

Spuriously, yes. Varicosities in and of themselves do not cause knee pain(s), rather the extremity in question typically aches, feels "full, " and occasionally sharp pains may be sensed along the vein or its tributaries. The lesser saphenous vein starts near the lateral, posterior ankle and extends up to the popliteal fossa (the space behind the knee). Plan: ultrasound to assess for reflux, a baker's cyst or dvt.
TO A DEGREE YES. I certainly see patients that develop leg pain from varicose veins. At times the veins can become inflammed and cause more pain. Usually, I do not see varicose veins cause knee or other joint pain. I cannot say it never will do it but if it does it is quite rare.
Leg but not knee. Frequently patients with varicose veins have other associated problems, often times not related to the varicose veins. The varicose veins around the calf could cause calf discomfort but should not cause any knee pain. You should have a venous ultrasound to evaluate the venous system in that leg and, if it doesn't explain your pain, then you may need an orthopedic evaluation.
Certainly possible. There is no question that leg and knee pain can be associated with varicose veins, this is especially true of leg pain. You should see a phlebologist (vein specialist) who can evaluate your veins with ultrasound. This will help to clear up whether your leg/knee pain might be related to your varicose veins or not.
Local pain only. Vericose veins can be locally tender, but they should not cause pain in near-by joints or deep in the muscle.
Yes. May have clot in vein which is called superficial thrombophlebitis. Try advil (ibuprofen) if you can take it as well as warm compresses a few times a day for 10 minutes each. Ultrasound will confirm diagnosis and evaluate for deep venous clot which is more serious and needs treatment with blood thinner.