My Manager told me as long as i did my job I would never have to worry about losing my job.is this an oral employment contract?

From what you've written, it does not appear that the promise from your manager is an enforceable agreement.  First, most states have what is known as a Statute of Frauds which requires some types of contracts to be in writing, and most of these statutes require contracts which cannot be performed within a year (unless one of the parties dies) to be in writing.  You claim that your manager promised not to fire you forever as long as you met the requirements on the list, a contract which would probably fall within the Statute of Frauds in most jurisdictions, and therefore would have to be in writing to be valid.  Also, you claim you signed another document, which did not contain the promise not to fire you, at the same time your manager made the promise not to fire you.  In most jurisdictions, the parole evidence rule would bar you from presenting any evidence of an oral agreement which contradicts the terms of a written agreement which purports to be the parties' full agreement.  I can't tell for sure without more details about the "list" you signed, but it seems as if that may have been a written agreement which would be contradicted by your claim of an oral agreement.  There are exceptions to both the statute of frauds and the parole evidence rule, but I can't tell from what you've written if any of them could apply to your situation.