Part of being friends with people is (obviously) just learning to get along with different types of people. Some people make this easier than others! To that end, I adore this quote by William Shakespeare:
"Love all, trust a few, do wrong to none."
To me, this quote means that we need to try our best to get along with people, and if we can't, to keep a respective distance. Don't get into gossip or bad mouthing, because that is behavior that makes you look very bad. We all can work on how we come across to others. A little self-awareness goes a long way.
But the other part of this quote, "trust a few," is really what speaks about friendship to me. You can't be pals with everyone. You can be cordial, and kind, but there are only a few folks in this world that you'll develop a true friendship with. I think that's good. It makes friendship all the more special.