"Associate yourself with men of good quality if you esteem your own reputation; for 'tis better to be alone than in bad company" - George Washington 

This quote means it is better to be alone than in company with bad influences. Instead you should be around people who do good in the world. For example stay away from people who do drugs. Stay away from those who bully others. Stay away from people who have no respect whatsoever. And mostly stay away from criminals because they can say that you were their accomplice. Be around people who perform random acts of kindness. Be with people who love to help others in need. Or better yet be alone. Because then you will get yourself in trouble if you do something wrong or bad. And when you are alone you could stay away from all trouble.