Actually I am in class 11 and I can't solve jee adv questions What should I do now?

You should focus first on your 11th class as it will help you to build strong base. After completing your 11th class syllabus you should focus on 12th class. Try to complete NCERT books for your preparation. You will able to solve the JEE Advanced questions when your concepts are strong. After completing each chapter try to solve as many as MCQs related to that topic. Refer past year problems to understand the exam pattern and level of questions. You can also solve complete mock test twice or thrice a week to judge and analyze your performance level. All the Best!!