Each of us comes to earth with a purpose, a path to follow with guides to help us along the way. The key to living a fulfilling life is to align yourself with your purpose and to follow your unique path.
How do we know we are on the right path?
Many religions have attempted to answer this question, but the short answer is: you don't. Unitivism doesn't teach "knowing", instead we become comfortable with discomfort and use our intuition to reach spiritual alignment. The more aligned we are, the more at peace we feel. This is our only indication and we must learn to trust that "gut feeling".
However, there is a structure in place to help you achieve that place of peace. Many famous authors have written books with exercises on finding your purpose.
Simon Sinek famously taught the art of finding your why to Ted Talk audiences in 2014 [https://www.ted.com/talks/simon_sinek_how_great_leaders_inspire_action?language=en] and again in 2021 [https://www.ted.com/talks/simon_sinek_how_to_discover_your_why_in_difficult_times?language=en]
Brene Brown has worksheets for uncovering your values: https://brenebrown.com/resources/dare-to-lead-list-of-values/
Erica Layne wrote The Life on Purpose Movement and offers a 21 question worksheet aimed at helping you discover your purpose.
These are all great tools to get your started. Another technique is just to take a look at your life and document how you spend your time over the course of a week. Ask yourself, is this how I want to be spending my time? Look at small ways you could spend more of your time doing what you love. Analyze how you spend your money. What your friends say is your best quality. As you take notice, themes will begin to emerge and you will start to see your path taking shape all around you.