just went to practice this song with just strums with holding the chords down for the song to see what happened.

hoping that it's the right thing to be doing as, I am finding this song and what goes with it frustrating.
so I am doing Down stop UP Down Stop UP and so on when holding a chord.

I am lost on the whole chunka chunka thing seems really advanced and the above says that it's a stage 8 thing really.
the video says we learnt about triplets in other lessons, yet I have been doing the lessons via the book and, I haven't noticed triplets as yet or shuffles. I must be ignoring something vital out completely.

I have only noticed the patterns in sets of 4s.oh dear this is going to be pretty hard work, but I do love the swing sound of the chunka chunka and it is a challenge worth learning, can't wait to give it a try when the times right.
now I am lost here as to what I should be doing and what I shouldn't be doing as the online video shows a chucka chucka technique straight away that wasn't in the previous lessons, if it was I have missed it somehow.
can anyone explain please if meant to learn this now or later? I wasn't sure to ask or not as, I felt not asking struggle on and pretend knew what was doing but, in asking was worried I'd look stupid.

thank you very much for replies
LOuise