Best Store credit card?

I was told to either get a small loan with co-signer which I do not have or a gas\store credit card b/c they are easier to get. However I do not want to make a bunch of inquires to see which one I can get with my fico scores only at 597/597/588 . I am thinking of trying Walmart but am unsure if my score will get me in or not.. does anyone know what type of score they are looking for? I am not looking to spend on these cards just use as I need too to establish credit! Which card would you suggest? if any with my scores the way they are!