Trigonometry, if it’s included, is very important for several things and could very well be included in precalculus. Check out the syllabus and book for what would be included.
I would also think about who teaches the class. If it’s a challenging class with a good teacher, you could learn a lot. If it’s easy, maybe you could learn it on your own.
I skipped Spanish 2 in high school. That would have been no problem if the Spanish 3 class was easy, but it wasn’t. So I worked very hard and got a lot of help to catch up.
What is the rush to take calculus?
Seems like you might want to take precalculus in the summer since it would likely be at an accelerated pace given the constrained time frame. Or you could maybe just go through it on your own. But just reading the book probably wouldn’t be enough. You would want to go through a lot of problems.