Joseph Campbell opened my eyes in saying that following my bliss puts me on a life track that has been laid out and waiting for me. The type of life I ought to be living becomes the one I am living. Living a blissful life becomes the journey.
A blissful person lives a magnified emotional state of fulfillment and happiness. I believe this comes from the all of the smaller collected moments of life as they continue to happen.
Helping your neighbour shovel his driveway.
Donating to charity so that a village can dig a well.
Giving that time and attention to an elder that is lonely.
Listening, really listening to someone in pain.
Delivering those food and clothing hampers to those in need.
If we help others, then we move towards becoming the people we always hoped we would be.
There is nothing outside of yourself that calls to you (except your mother, and you should call her back). Otherwise, if you believe you are a blank slate to begin with, then everything you sense builds upon each new sensory experience.
At some point in time, you will project beyond yourself and perceive this as a calling. It might be life, a profession or a moral epiphany. But all of this comes from within. This means that you have to do a bit of work to discover this calling. It might come to you as any wild animal might, but otherwise any experience worth having requires effort.
If you answer this call to yourself, then you are also following your bliss. Therein lies the happiness you are seeking.