This is a very good song to learn for those who are just starting out in guitar as the most popular way to play this song also happens to be one of the most easy full downstroke strumming pattern. You can literally full downstrokes throughout the entire song and still song perfectly nice or you may follow my way of playing which is a combination of plucking and strumming.
Every bar is 4 counts of downstrokes and for me, i will add an accent on the third stroke and add a few upstrokes to it. The only part one needs to watch out is the bridge instrumental after second chorus, because that is where the key increase then transition back to original key. You will see B-chord, A-chord which requires a lot of practice to nail down the position and the strength to hold the note. Other than that, this song overall is such a beauty classic, easy to get grooving and had people singing along with you.