Don't worry about making big sentences, start with single words. Most students make the mistake of jumping into long, complicated sentences. Don't do that. Begin with simple words, and your confidence will grow step by step.
Because let's be honest, English alone is not enough. Confidence, expression, and body language are equally important. Interviews are not just about words, they're about how you present yourself. So, practice in front of a mirror every day, you'll see a huge boost in your confidence.