You can use User Properties variables to store user data and use autoskip prompt in case these variables already contain a value. However, the only problem with this approach is that sessions get restored every 24 hours so it’s not a good idea in case you want to fetch the user data even after 24 hours.
Alternatively, you can store user data in the database and fetch user data from the database (using a unique key like email or phone number) when users visit the chatbot again.
Live Agent feature is not available for free WhatsApp integration. You need to get WhatsApp for business account in order to enable Inbox for your WhatsApp number.
You can enter the same sentence in Tools > Test Your Bot to check if it’s invoking any journey.