What happens if you take amoxicillin 500mg 4 hours early than you are supposed to my doctor prescribed it for every 7 to 8 hours?

You take penicillin exactly as your doctor has told you to take it - do not take it if you have not seen a doctor and actually been tested to make sure you have an infection. It's not going to help if you have a virus, and will just make you resistant to it so it won't work in the future. Penicillin is usually taken every 6-12 hours however.