Hello, Disclaimer: I did not even now before your post what BPMN stands for... there is a comparison of BPMN sotfware on Wikipedia: https://en.wikipedia.org/wiki/Comparison_of_Business_Process_Model_and_Notation_modeling_toolsAmong these solutions I would take a look at Flowable (free license, relatively clear presentation for a newbie):
https://blog.flowable.org/2020/10/07/flowable-6-instant-gratification/