I have High LDL Need Help!

Please give me a answer to this Im 21 year old male very lean 53kg Total cholesterol 288 LDL 207 Triglycerides 85 HDL 63

non fasting lipid profile Total 321 LDL 241 HDL 69 Triglycerides 55 My doctor Said its familial and put me on crestor 5mg But my parents hadn't any cardiovascular event,I don't know what to do.