Autosuggestion for driver is not working on Selenium on Eclipse

I am trying to create my first automation test and when I try to get autosuggestions for driver ( the get(string) one), nothing appears. Also multiple error appear. IS there anything, like other extensions, that I need to install or what might be the problem?

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;

public class Demo {
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        System.setProperty("webdriver.chrome.driver", "C:\\test\\chromedriver.exe");
        WebDriver driver = new Chromedriver();
        driver.

    }
}

The following errors appear:

1. Multiple markers at this line
   • The type org.openqa.selenium.WebDriver is not accessible
   • Must declare a named package because this compilation unit is associated to the named module 'Introduction'(for line 1)
2. The type org.openqa.selenium.chrome.ChromeDriver is not accessible (for line 2)
3. Multiple markers at this line
   • WebDriver cannot be resolved to a type
   • Chromedriver cannot be resolved to a type( for line 10)