Finding a lawer

How can i find a lawer I have no money to pay to figure out all this mess

You will have to expand this queston. If you have oil & gas interests or money in suspense with a company, a lawyer may be willing to work with you. However, based on what you posted, there is not enough information to give advice on.

My Great grandfather EH Heffington and his wife my grandmother has mineral rights in Howard County and other places maybe in Ok and Mississippi I have a lease with Oxy we only receive the lease payment in 2016 or 2017 now they say I need owner of heirship

It appears that you will need to do a probate in Oklahoma, and some estate proceedings in Texas and Mississippi. It also appears that you have or may have money in suspense with Oxy or its successor. If this is the case, most lawyers would agree to do the probate or clear up title in exchange for receiving the invoiced money from the company. In other words, their bill gets paid off the top and then the rest goes to the heirs. Before talking to a lawyer, it would help to a) have a title requirement in writing from the company, and b) an approximate amount of money held by the company.