The prosecution generally can’t call you as a witness in your own trial. The defense could, but if the defense does then the prosecution is allowed to question you.

Apparently it’s complicated, but if you answer some questions and then stop answering questions, it could put you in a week or legal position than if you had stayed off of the stand to begin with. According to the below website, it’s possible that the judge could order you to answer questions if you tried to stop halfway through. But even if they didn’t, once you’ve gotten on the stand and remain silent, the prosecution is allowed to comment on your refusal to testify, and the jury might take that into account when it deliberates.

From a practical standpoint, trying to get on the stand and answer some questions but then stop before saying anything that could theoretically be incriminating is incredibly difficult to do. Even things that you don’t think might make you look bad could somehow make you look bad in certain circumstances that you cannot predict, and it’s difficult to say exactly the right thing in unambiguous terms when you’re in a highly stressful environment like a trial.

https://www.nolo.com/legal-encyclopedia/your-fifth-amendment-right-against-self-incrimination.html