Maybe a little too late, but yes, I want to think more rational. What kind of disciplines or subjects do you recommend in those fields? I'm a ongoing undergrad

Maybe a little too late, but yes, I want to think more rational. What kind of disciplines or subjects do you recommend in those fields? I'm a ongoing undergrad in Computer Engineering, and I have a little bit of background in Math, it is not so great, but is solid. But philosophy is something I'm a enthusiast but do not have any solid knowledge.