To solve a problem like this you need to break it down into smaller pieces so that you can build up some confidence about what is working and what is not. When you share a problem like this as a question it helps if you can give us some idea of your experience level and of what you've already done to debug the problem – that helps with avoiding telling you what you already know and makes it easier to focus in on where the problem might be.
From what you've said it appears that you have things working well enough that you get a display on the LCD but it does not represent a meaningful distance.
Looking at your schematic the first thing that comes to my mind is that you have the ultrasonic sensor at the opposite end of the breadboard from the LCD. Many breadboards split their power rails at the middle. So start by confirming that you have power to the sensor.
After that, double-check the rest of your wiring.
The next step for me would be to confirm that I understood the sensor and to try and prove that it was working as I expected. Look for some sample code that is known to work (often the site you bought the sensor from will have links to beginning tutorials or code samples). Try that to see if the sensor works with the sample code.
If that doesn't work then check to see what you can do to prove the sensor is good (or bad). You might also contact the vendor to see if they can give you advice on proving that the sensor works.
Basically, break the problem down into "bite sized" chunks and work through it one step at a time, doing the simple stuff first. Try not to assume anything…