Trying to raise my fico score. Secured credit card or not

I have a question concerning bringing my fico scores up, if I go and get a secured credit card that reports to all 3 bureaus today will that bring my fico up or down when the credit card creditor reports it?
I am trying to bring my scores up I have a 602 at Trans union 585 at experian and a 595 at equifax.
And I also have 2 credit cards already one which I have had for 5 years they just increased yesterday (limit now is 1300.00) And the other one I have had for 6 months coming march they will increase it to 400.00. I always wanted a department store card such as walmart, do you think with these scores I can get approved for one?
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it takes 1 year to get a credit line rated.
no one can say you pay well unless they have worked with you for 12 months or more.

if you have 3 credit lines that report, concentrate on them and get no more