Help me group my muscles for lifting. I don't want to overtrain?

What you want to do is work your lower body too. Don't just focus on upper or you lose a lot of strength. If you want to you could just do 3 days a week (Monday, Wenesday, Friday) and do an hour an a half or so of good full body workout which gives your muscles relapse time to grow. Also you can do cardio on the other days to train your heart to be able to stay up with your body. Make sure to do core work as well which can help almost all of your lifts.