We are new & we need info on being vested in a company instead of getting a 401k

If it sounds like I don’t know what I’m talking about, it’s because I don’t Lol Which is why I came here to hopefully gain some knowledge. My spouse’s company decided to stop doing 401k & vest their employees in the company. After almost 15yrs w/ the company, they are tired & ready to find some place back home to settle down, be around family & friends, & have a more relaxed career. However, we don’t know if we will be penalized for cashing those stocks out when they leave. I know my sister paid something like a 30% fee for cashing out some of her 401k early. Can anyone explain how this works? We didn’t want to ask directly because we aren’t ready to exit just yet & didn’t want to raise suspicion.