It most certainly is something you need to fight because a DWLS 3rd Degree is a criminal charge with a maximum sentence of 90 days in jail and a $1000 fine. If you do not show up to court then there will likely be a warrant issued for your arrest. I would recommend contacting an attorney before you go to court because often times there are ways to make these go away.
Yes, this is "worth fighting," in that your appearance at your scheduled court date is mandatory. You've been charged with a crime, not a traffic infraction. The exact extent you want to fight it is what matters most. If your license was suspended and you were driving, this is usually an open and shut case, that can be resolved with an amendment of the criminal charge to a traffic infraction (no valid operation license), or some community service hours, depending on what the prosecutor is willing to offer. Whether you receive an offer also depends on how many prior DWLS charges you have.
You'll need a lawyer when you show up to your arraignment. The court will ask you if you will hire your own, or apply for a public defender. If you qualify for a PD, just go that route. These cases are pretty easy and are not time demanding. If you don't qualify for a PD, you should definitely hire a private attorney. The fees you'll expect to pay shouldn't be outlandish because again, a DWLS 3rd is one of the most minor criminal charges you can get.
If you feel that your license was not really suspended and want to fight this all the way to trial, you have that right, but you will definitely need to hire a private attorney.
I agree with the other commenters: this is something you need to take care of and ignoring it will make things much worse. You may be able to get this amended to an infraction, which would be hugely beneficial. Although driving while suspended 3 is about the least serious criminal charge a person can face, it's still a crime and needs to be taken seriously.
As mentioned by my colleagues, this is a criminal charge and you should obtain a lawyer to help you make sure you can obtain the best outcome possible. Feel free to call my office if you would like a no-cost consultation to discuss this situation further.