Why is having high cholesterol bad?

I was just at my doctor and was told I have high cholesterol after getting my blood work results back. I didn’t have much time to go into detail with my doc on the factors associating with that. The normal average healthy range is 100 and below. I’m at 130 in cholesterol level. So, why is it bad to have high cholesterol? I was told to eat more high fiber foods which will help and to make sure what I am eating does not have any cholesterol. What risk factors come with high cholesterol? Also, I only eat twice a day and so are there any supplemental vitamins to take?