Waves and oscillations are probably my favourite topic to teach! Every time I revisit it my understanding of it changes and improves. So take your time and you'll find out just how much there is to be fascinated by!
Make sure you have a really good working knowledge of all the basic wave quantities and wave behaviours before you go on to tackle the new ideas of Huygen's construction, standing waves and interference.
You'll also discover how a simple wave form is related to trigonometry, using sine and cosine function graphs to draw wave forms accurately. So that means that triangles, circles and waves are all inextricably linked! Amazing.
Waves explain how we communicate, how we see, without knowledge of them we wouldn't be far out of the dark ages!