Go to your local USCF club. Join and play. This will get you a rating and introduce you to other players. Once your strength is known perhaps you can get a instructor. Your instructor will be able to spot your weaknesses and help you overcome them far quicker than you can do this yourself.
edit - As per the comment below, $40 to join the USCF, less if you ask them for options. Beginner's gear is $50 (example, ymmv, no affiliation, etc etc) and will likely be completely adequate for years. Then there are state memberships, etc. It's a racket to be sure but in the scheme of things... chess is a cheap hobby.