Ask HN: How can one offer free services to work with VCs/startups

I really wish to work with some VC firms and Startups to offer my expertise for free and just getting more involved with them. I am not really sure how to approach them or do they even need such help.

I do not wish to charge any money but instead just want to be more involved with the community. (I currently work as a data scientist/engineer by profession.)

Has anyone here tried such thing before?