New to using metro and need help!

I’ve taken a job that is in downtown very close to the courthouse and I decided I’d rather take the metro to get there instead of driving my car . I am in the cloverleaf northshore area so I have a park and ride location on maxey rd and wasn’t sure how to understand the system. I’ve never rode a bus or train for downtown so I’d like some help and tips . The job is from 8:00am-4:30pm weekdays so I know those are the busiest probably so I think to board a bus at 7 would be good to make it by 7:50 ?