If it is a valid narrowly tailored non-compete, your former employer can seek an injunction preventing you from working. I know this doesn't help much but legal fees to defeat such a action, without guarantees, can run from $5000 to $50000.
If you'd like to discuss, please feel free to call. Jeff Gold Gold, Benes, LLP 1854 Bellmore Ave Bellmore, NY 11710 Telephone -516.512.6333 Email - Jgold@goldbenes.com
You are at risk if you go to work with a competing employer unless you first bring your contract to an experienced employment attorney for review and advice. We have no way of knowing what this will cost you. Each lawyer/law firm sets their own fees.
Objectively, what happens if you start working is that the former employer will likely go to court and seek a restraining order against you to enforce the non--compete agreement, if there is a noncompete agreement. You never actually said there was one. In fact, it sounds like you might be an independent contractor, in which case it will be an uphill burden for other party to get an injunction. Until there is an injunction, you are obviously free to continue working, although you risk increasing any damages that are ultimately assessed against you. You really need to see an employment lawyer or intellectual property attorney about this. My guess is you are looking at at least $10,000 in legal costs minimum with the sky being the limit, depending on what the other side wants this fun to cost you.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.
Non-compete clauses are usually narrowly tailored to a reasonable time, scope, and geographical area. For example, the company can't make you sign a non-compete clause that bans you from working that specific trade anywhere in the country, or for 20 years, or other unreasonable restraints. However, they can ban you from working in the same or close geographical area and for a reasonable amount of time. Your fact pattern doesn't give enough information to give a better answer, so talk to a lawyer about specifics.
If you continue to work expect legal fees. Talk to a lawyer first.