I guess there are all/many types of them? Friends who listen to you when you are feeling down, those who smile with you when you are happy, those who cry with you when you lose someone, and those who celebrate the little things just to dance and have a good time. 
But even though most will say that it takes two people to have a friendship, I don't think that's totally right. I think that you can be your own best friend. I know that sounds weird but I believe that you have to treat yourself as you would want to be treated by others. You have to support yourself, encourage, like, and help yourself grow and get better everyday. 
That little voice in your head is yours and you can choose to listen or ignore it. And it seems to me when I ignore it I don't get anything accomplished and kinda give up. I get myself down and I have to look outside of me for help. That's when I look to my friends for help. And that is where you come in. My friends know who they are and tend to touch base just when I need it most. 
It may sound strange but I have had good friends who I have never met in person. Though technology I have made friends online and I have talked to them more than others in person. I say this to those who are afraid to step out there and meet total strangers. Sure you still have to be cautious but once you start talking to people (really talking) you can tell if they are for real or just playing around. And when you do meet people you will find out we are all alike with similar problems and things that make you smile. You can receive help with issues you are facing as well as help people with their problems in life, both you and them will benefits from these friendships. Ask me about "Making Friends with Candy" sometime when you have time to listen to a true story too long for me to write here. It is a story I will cherish forever the rest of my days here on earth. 
Oh well back to friends. How many do you have? What would you do for them? Anything you wouldn't do? What is a "real" friend? You need to answer these questions for you. And when you are done with answers go make more friends. You can be a friend just by smiling and saying hello to that person you pass in the hallway at work or a total stranger at the mall. Push my "Add Me" button or anyone that looks interesting to you and start a friendship.