The ability to read a wave is acquired mainly with sea time, with training! But there are a few things you can take into account to read one.
3 tips to keep in mind when reading a wave:
Analyze the sea and the waves and try to find patterns, similar repetitions. Observe live from out of the water, underwater with diving goggles, take pictures, use a drone to see from above or take advantage of beaches like Ericeira, Santa Cruz, Consolação that allow us to look at the beaches from above;
Try applying these zones in different waves, more or less perfect, to the right and to the left;
Feel the different energies of the waves just by bodysurfing, without any props or with just a few duck feet. It is one of the exercises we do regularly at Good Surf Good Love Surf Academy.