Severance offer, what should I ask for? after 3 years as a welding apprentice

My manager said the package is final, but the letter gives me time to review. This is my first time dealing with any of this. There is a non-disparagement clause. Should I see a lawyer?

Thanks for writing this out. I went through something close to it 2 months ago, and it got easier once I kept a simple log of every call and form.