I have a question concerning internet security, anonymity and pay VPN services.

{To make a long story short}
My mother and I have not been able to open a Facebook, Twitter account nor the like, in years due to my estranged stepfather always finding us.
He is an ex-policeman and whenever we open an internet account, he asks his friends still on the force to pull some strings for him and supply him with our IP address and location.

My question is: How can I open a social media account and fully protect my privacy so it would require a warrant stating a legitimate reason for law enforcement to obtain my IP address/location and for it not to be supplied as professional courtesy to cops doing a favor for a friend.
I have been told so many things…... to use pay VPN service but not a proxy to protect my privacy as it would do not release any information without a valid warrant and it would be accepted by Facebook and email services to open new accounts.

* Please,I need helpful advice not smart-aleck comments.
Yes,I am well aware that it is impossible to remain anonymous from Big Brother so spare me the speech.
No,I am not planning on committing any illegal activities and I know that if I did, it would take the government micro-seconds to find me.
Also,I don’t need advice of how to deal with my stepfather.