Saving a checkbox's state, and then loading it

What I'm trying to do is have a setting menu pull up when a button is pressed on my main menu (settings menu is implemented as a separate activity from my main). For simplicity's sake, assume that my main menu is blank except for 1 button that pulls up the settings menu. In the setting menu, there is one check box and one button "Done" that returns to the main activity.

How do I save a CheckBox's and load it (what should the code be, where should I put it, why, etc) ? I've tried googling it, and trying to replicate the results, but I can't seem to get it. 2 things have happened so far: nothing has saved, or my program crashes.

Once I have the information about the checkbox saved, how am I able to access this information from my main activity @I want to be able to run certain code based on if the user checked the box or not?

some results that I've landed on and tried: How to save the checkbox state? - android Saving Checkbox states

(Please keep in mind that I'm completely new to this)

Code for Settings.java:

public class Settings extends ActionBarActivity {

    //char boxChecked = '0';
    @Override
    protected void onCreate(Bundle savedSettings) {
        super.onCreate(savedSettings);
        CheckBox cb = (CheckBox) findViewById(R.id.checkBox);
        SharedPreferences sharedPref= getSharedPreferences("CHECKED", 0);
        boolean wasChecked = sharedPref.getBoolean("check", true);
        cb.setChecked(wasChecked);
        setContentView(R.layout.activity_settings);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_settings, menu);
        return true;
    }

    public void clickedDone (View v) {
        finish();
    }

    @Override
    public void onSaveInstanceState(Bundle savedSettings) {
        CheckBox ch = (CheckBox) findViewById(R.id.checkBox);
        if(ch.isChecked()){
            SharedPreferences settings = getApplicationContext().getSharedPreferences("CHECKED", 0);
            settings.edit().putBoolean("check",true).commit();
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}