Jupyterlab is an amazing environment to play around in. There are some features that can make the experience even better. A collection of them will be demonstrated here.
The python kernel can be busy which is the main reason why your notebook is left unresponsive. You should also not assume that autocompletion or documentation can be fetched for objects that do not exist yet.
Feedback? See an issue? Feel free to mention it here.
If you want to be kept up to date, consider getting the newsletter.