The first thing that you would want to do is make sure you qualify for a mortgage. You will need to have good enough credit and income to qualify, and have a sufficient down payment. You will need at least 10% plus closing costs for the down payment. Although it might be possible to get a seller's concession for closing costs, that has become more difficult in today's market because the unit would have to appraise for the higher value. As a first time buyer, you may be elligible for a SONYMA loan that will give you a lower interest rate. Call me to discuss anything you would like to as far as mortgage qualification goes. I can be contacted at 516-972-1687.
Once you know how much you can spend, you can try various website to see what is available in your price range and see if it would be sufficient for your needs. You could then contact a few realtors. Speak to them first and get a feeling for who you might want to work with. You can then have the one you choose show you some apartments that you would like to buy.