You should be able to play this song in less than a week, if you can't, please play songs from level 1
The best way to learn this song, or any other song, is to watch the video at least 10 times. Concentrate on the actual fretboard first, and see where you need to put the fingers, then see the TABS and look at the numbers you need to play. Finally look at the actual music notes and see how they go up pr down.
Once you are familiar with the song, and how it sounds, then print the music score PDF below.
Now, with the actual music sheet on your hands, play the video a few more times and put your eyes on the paper, and read along with the music, listen to the song while looking at the music sheet, and the TABS.
Do that a few more times and with your index finger, pointing at the notes as the same time as you are listening to the music.
Now, count the measures in the song, in this song A Little Piece Of Heaven, you have 8 measures. And you have six days to play the song. (The seventh day, you just relax and play the song for your friends or family.) So, if you have six days to play 8 measures, you have to learn a little bit more than a measure per day. Now look at the music and you'll see how simple it is, Right?