“ Associate yourself with men of good quality if you esteem your own reputation for tis better to be alone than in bad company.” - President George Washington

What this quote means is not to hang around with the wrong crowd because bad people will try to influence you to do bad things.  An those bad people will ruin your reputation. So it's better to be alone than to be around bad people. At least now you won't be influenced to do bad things anymore you will be choosing the right.