Joseph Campbell’s “follow your bliss” means that 
by pursuing what is most fulfilling and passionate to you, you align with your authentic self and the universe will provide opportunities to support that path. It is about identifying your unique passions and talents and having the courage to follow them, even if it means deviating from a planned path. According to this quote from the Joseph Campbell Foundation, this deep sense of purpose will open doors where there were once only walls. 

How to follow your bliss
Listen to your inner voice: Pay attention to what genuinely excites and draws you in, even if it’s not a conventional path.
Identify your unique talents: Recognize your own unique gifts and passions. Your bliss is personal to you and not the same as someone else’s.
Embrace uncertainty: Recognize that following your bliss may feel scary, but it is a way to live your own unique adventure rather than following someone else’s footsteps.
Commit to your path: Understand that this isn’t about fleeting pleasures but about a deep, authentic sense of purpose. It requires commitment and may not always be easy, but it is the life you are meant to be living.
Trust that doors will open: Campbell believed that when you are true to yourself, you will start to meet people and find opportunities that open up new paths for you.