The LCD display is an I2C device. Make sure to read our separate I2C instructions for other important details on wiring up any I2C device.
Here are further instructions on making the accelerometer work. Note that in those instructions, you're directed to install a library that you obtain from a zip file. To do so, first download the zip file from that site somewhere onto your computer. Then, in the Arduino IDE, go to the Sketch menu, then choose Include Library, then Add .ZIP library. Find and select the zip file you downloaded.