Do I need a desktop for engineering major? Is a laptop enough? Will a desktop help ?

From Google search (but I can’t be certain it reflects current situation):

"A Macintosh is fine for general-purpose use, but is not a good choice if you want a computer that can run engineering-specific software, which is mostly Windows-based. You will need to run Microsoft Windows on your Macintosh if you want to run Windows-based engineering software.

Good suggestion to check with your school’s Computer Services Department. At Lake Jr.'s STEM university all underclassmen must lease the laptop recommended by the school. He continued with the school laptop throughout his time at the school. It’s just simpler and the maintenance is free, including free replacement, no questions asked.