It is intended as a first-stop, for information. You cannot buy anything through Trulia; you will need to contact a Realtor to see if it still available, what the details are, and to make an offer.
If you do no have an agent, there are several qualified experience professionals here, find one in your area and ask for a consultation. Then decide if the two of you are a fit to work together. Once that has been accomplished your agent will set out to help you achieve your real estate goals.
Have an amazing day!