There is NO genuine (natural) purpose in life, even writers (included in the bible) admit that.
Here's a few texts (using ESV)
1 peter 1:24 - "All flesh is like grass and all its glory like the flower of grass. The grass withers, and the flower falls"
Likely this author drew on previous writings to make his point (which was to have a new life with jesus) which may have been a text like Psalm 102:3
My days are like an evening shadow; I wither away like grass.
The author of James draws on other imagery
See James 4:14, What is your life? For you are a mist that appears for a little time and then vanishes.
Various texts could have been in that writer's mind, but Psalm 144:4 will suffice...
Man is like a breath; his days are like a passing shadow.
There's lots more all making the same points (seek god's purpose) and I often used these texts in my JW life, where I imagined myself as a shepherd caring for god's little lambs.
Those writers imagined that there was a creator who had a purpose for them. Any contemporary christian likely thinks the same way- but what happens when the scales fall from their eyes and they see clearly that it is veery unlikely that there is any such creator.
That is your position, isn't it. So what to do - look around you and you see people doing all kinds of things, without religion being the most important thing in their lives.
After I was kicked out, I focussed on my work, learning to use CAD in my design work. I'd also (as a kid) loved history and would spend hours reading history books, So at age 75, I went to University to study Asian history, I was fortunate enough to have a professor who had also worked in the Australian diplomatic service and served in many Asian nations. I spent ten years attending lectures at two leading (Sydney) universities, and reckon I know have a great all-round understanding of Asia. Was there a function to all that study - many would say it was pointless, no use to me or anyone, but look closer - there was point - personal satisfaction. If the rise of Asia is in the news, I can understand the truth or not of various statements. Yes, again that's just my personal satisfaction.
But in the end, that's all anyone has in their life. Personal satisfaction.
So maybe that's an angle to consider. Now you're free, what can you do to give you more personal satisfaction. You're free to set your own goals and purpose in your life.
Good luck in your search.