It was your first semester. If you look, most schools will look past the first semester GPA with a good letter with reasons.
Have you take any business courses yet? These will be more important than the engineering courses, in your case.
There are two options:
Do another semester where you are. This will show persistence, but depending on your financial situation, it may not be the best option.
Attend community college and graduate with an Associates before going to a Bachelors program. I have found that this has benefitted people, and it has let them really sample coursework and make sure that it is what you want to do. You may even find that there is something more specific than business that you like. Also, the cost is a lot less.
I am graduating with my Associates in August, and I have found it to be very useful. I was originally a business and biology double major. Then, I realized that business was really boring for me. I was able to take all of biology classes and catch up fairly quickly without loans!
A 2.1 GPA will eliminate your chances of transferring to another university at this time. Stay at UIUC and try and do an internal transfer to their business school.
A 2.1 is vey bad. Were you focused on the party scene or are their other reasons for your poor performance?
Get your GPA up before even thinking about transferring. There’s nothing wrong with changing your major to Business within UIUC but get the grades up before you attempt to transfer schools.