Everyone’s different, so it’s hard to give advice without knowing your specific situation or what kind of grad school you’re thinking about. But I will say, grad school is not “undergrad-plus”, it’s an entirely different thing which is largely self-directed. It can help to have a couple of years doing something else to clarify your thinking about what you want to do in grad school. But: talk to your advisor and the career center also before you choose, I’m just speaking from the experiences I’ve seen.