if you believe free will is simply part of a causal chain
then free will is reduced to an emotion, a feeling you have when you make an apparent decision
if you believe free will, as it is traditionally defined, allows someone to "change their destiny"
then you are delusional
I believe nothing. But I do place probabilities high that there is no "destiny," that Now is the only thing that's real, and that We, with Our free will, co-create the Now.