I have a prescription for azithromycin 500mg daily 10 days. i took my first dose last night at 9 p.m. but can i take my next dose earlier?

Yes, no problem: You can take the second dose several hours early, no problem. Then continue one dose daily. Azithromycin is very long acting; each dose is in your system for a week or more. Take it once a day but don't worry about timing. It needn't be the same time every day -- although a regular time is still a good idea if it helps you to remember to take it.