Sign in and open the "My Lessons" page.
Tap the "Onboarding" button ("Let's personalize your learning!").
After signing up, the window "Welcome to the updated version of our website!" may also appear. "Start Now" opens the same questions, and "Do It Later" closes the window.
At the question "Who do you want to schedule a lesson for?" choose the details and the age, and tap "Next".
Answer the next questions. They change with the age: for example the name, the current and the wanted English level, the goals and the interests.
A question doesn't suit you now? If the "Skip for now" button shows, you can tap it and go on. Questions marked "*important for completing onboarding" have no skip.