we do not share your data with anyone and there are many ways to control the visibility and storage life of your data here.
but the internet is a public space and you should always assume your data could be compromised.
be smart with your password, use tor or a vpn, and use pgp for sensitive communications.
Best place for noobs here don't worry about it. 1 tip though - posts on your own page are pretty invisible so if you have to axe somebody do it here or on the sellers page or wherever.→