For the first time we'll be using both hands to finger this note. Hold down the three keys with the left hand, just like you do to play the note G, but now also add the index finger of the left hand as shown below:
We're now starting to have enough notes to play some famous tunes.
And another famous tune - Czech composer Antonin Dvorak's famous 'Largo' from the New World Symphony. You can come back to this tune once you've learned a few more notes and play the full version on 8notes here.