Let go of the past. No it isn't easy but you can do it, I assure you. Once you let go of the past, the void can be filled with thoughts of the future. Get rid of those too. Now the void is filled with the memories you make every day. The present is filled with love and happiness if you search for it. So long as you wake up and say "This is going to be the best day of my life," it will be.
Fall in love. There are so many things to fall in love with- puppies, poems, people, memories, ice cream, etc. The life you lead will be full of people who try and take advantage of your heart. Don't let them. Instead, surround yourself with people you love and who love you in return. Find someone who will leave you voicemails of them having a conversation with you as if you had answered.
Go on adventures. Plan a trip to another country and follow through with it. Take the train to a stop you've never gotten off at and make new ties there. Call an old friend and drive around; the adventure there is learning what you have missed in the meantime. Explore another person and learn all of their quirks. Cover your eyes, spin around, and go in the direction you're facing when you open your eyes. Count to three, run free, adventure hard.
Read something. Whether it be street signs or a classic novel, let the pages run through you. Delve into Shakespeare or start learning about astrophysics. Reading is the core of learning, and learning is the core of human existence. Read in a room with no windows so you will not see the days go by. Throw your horror comic across the room because you have the spooks. Eat a tub of ice cream because of the entirety of "If I Stay." Make friends with the characters in "The Hunger Games."
Make music. If you don't play an instrument, learn how to. Pick up a ukulele and go through YouTube tutorials, or blow across the bottle to make resonation your song. Sing wildly with your friends on the bus to school. Kick holes in walls if you feel angry. Clap your hands for the boy on the train trying to make an extra dollar. Tell someone you love them. Making life timeless is easy.