No, you can’t turn off just the steering piece. You can turn the entire lane keeping system off. It will likely help your situation if you take the time to sit down and peruse the owners manual for your vehicle. Its purpose is to describe all the functions and operations. I know it’s easy to just ask on a forum and let someone who has put in the effort to learn, or just over time & experience has absorbed the knowledge through their own trial & error provide you an answer.
Really, download your version onto your phone and always have it handy…