Should i just drop my trig class? and take it in fall?

I'm going to be honest! This teacher is nice, but he is boring, and if he was just boring i would be okay with that. But in the beginning i understood what he was teaching but then he lost me. That's not just the problem. But when I got help from my friend on the lessons i understood it better. She told me he must skip steps. I failed the first exam. Doesn't give a study guide. Did i mention it's summer school. So the test are like every week. So i check next fall teacher's and one teacher goes step by step and my friend said she really understandable. So should i drop it??