The bad news is...
One of the things that feels most weird about learning grammar is that you are being asked to learn alien-sounding rules for something that you already know how to do intuitively.
So these lessons are going to feel awkward and clunky at times, and that can be extremely frustrating: “Why do I have to do this? I already know how to speak and write! Why do I have to learn all these weird names and rules?”
As you do these lessons, be patient, and keep some perspective.
Keep reminding yourself: we’re here to learn about patterns in our language, and become familiar with tools to describe the components we use every day.
You don’t need to memorise everything in these lessons (at least we don’t think you do; your school or teacher might feel different).
What you want to walk away with is the ability to look at a sentence and break it into chunks, and understand basically what those chunks do.
Getting exactly the right terminology is not as important as being able to pinpoint what each part of the sentence is doing, and be able to think about what might happen if you changed it.