J24 Good first boat???
A J-24 would be an excellent boat for what you want to do. They have good light air performance and so are nice boats on the Sound. A $5K J-24 is not likely to be in competitive condition and would need a fair amount (sails and bottom fairing) to go racing. You will need to have the boat surveyed because J-24''s in that price range are prone to hull and deck delamination and also problems at the keel stub.
Still you can find sound but not competitive J-24''s in that price range. It should hold its price quite well and serve your purpose quite admirably. You might also look for a Kirby 25 or a Capri 25 which should be similarly priced but harder to sell. The J-24 should hold its price as well as the Catalina 22, be better built and easier to sell, sail much better and faster.