Regarding dietary fat, the usual advice to lower LDL levels is to avoid saturated fats, which are common in the fat from red meat, dairy products, and coconut and palm oil. With red meat, choose the leanest red meat to minimize the saturated fat.
However, even more important is to avoid trans-fats from hydrogenated oils, common in margarine, shortening, and processed foods (avoid those that list hydrogenated oils). Fried foods in restaurants may also be made with hydrogenated frying oil. Trans-fats raise LDL and lower HDL, so they are worse than saturated fats (which may raise HDL as well as raising LDL).
Unsaturated fats, common in fish and vegetable source other than hydrogenated oils and coconut and palm oil, are generally considered favorable for lowering LDL levels.
Increasing exercise raises HDL levels.
VLDL / triglyceride levels are raised by sugar and alcohol, so cut back on those if your levels are high.
(LDL, VLDL = bad; HDL = good)