I'm more of a black/white person, so I did much better in Algebra, Trig and Calculus. I hated Geometry. Those that do poorly in Algebra, etc tend to do really well in Geometry. Just has to do with how we process things. Geometry was too abstract for me. If you did poorly in Algebra, you're probably going to do great in Geometry.

As for dropping out - you are sealing your future if you drop out of high school. And not a very good future, I might add. In fact, if you don't have plans to attend college, be it a technical college or a university, you're going to struggle to get a good paying job. There are good jobs out there with just a high school education, but it's going to be a harder road for you in the professional world.