Want to create a search feature for my website

I want to search-based website like tripadvisor. In example; i want to create a similar search feature like tripadvisor's "Where are you going". I am not really familiar with this topic but I believe this could be done by Ajax,php and sql programming language. Right now, I'm looking to use free script,plug-in or tutorial to get this done. However, I can pay small fee too.Please advise