There's a dangerous contradiction there. If you are an independent contractor you are not an employee. If you are an employee you are not an independent contractor.
I'm guessing that you are being misclassified as an independent contractor for the "employer's" nefarious purposes. That, in itself, can cause you trouble.
So, if you haven't signed it yet, I suggest you refuse to sign it because it's the kiss of death.
It's legal for your employer to have you sign a non-compete.
It's legal for you to refuse, but you'll probably get fired if he's making an issue of it now.
It's illegal to classify you as an independent contractor if you aren't. You can find out more about that on the IRS website.
You will still be able to start your own firm. Nothing "prevents" you from doing that. Unfortunately, nothing prevents the employer from suing you into the poorhouse.
My advice: Don't sign it.
No matter what.

