As some have said, a stellar portfolio is definitely needed. As far as getting it to the right people, start here.
https://disneyimaginations.com/
A friend of mine did this competition a few years in college (didn't win) but is today an imagineer because of the people she got to meet while doing it.
Another great way to get in the right direction is to become a CM on the Disney College Program during school. You won't be doing anything having to do directly with imagineering but you will have the opportunity to take classes about engineering, network with folks in the field and put a gold star on your resume for the future. Check disneycollegeprogram.com and disneyinterns.com for more information about the programs offered.
In the meantime, keep brainstorming, study hard and get good grades. In an job that is as competitive as imagineering, you need to have as many tools in your tool belt as possible.
And, always have a back-up plan. GOOD LUCK!!