Monounsaturated fats lower LDL whitout affecting HDL the good cholesterol. Trans fats increase LDL while lowering HDL so avoid those. Saturated fats even long believed to be bad for you are not that bad for you as the countries with the highest saturated fats in their diet also have the lowest rate of deaths from heart disease. Furthermore some sources of saturated fats can increase HDL levels. Polyunsaturated fats (omega 3 and 6) are good fats but you need to have the correct ratio's between the two, most people consume a too high amount of omega 6, the ideal ratio is close to 1:1. Polyunsaturated fats are also less stable too cook, forming free radicals. Monounsaturated fats are suitable for cooking.
LCHF diets tend to lower the bad cholesterol. Don't be affraid of the high fat since your sources will contain more good fats than bad fats.