I have the same. As for the Theme change, there's couple of them, you can navigate to it via clicking your username at the top-right corner > change style. You should see something like this: https://i.imgur.com/RdcKGjF.png
Hey there, I've recently re-activated my account after some time of inactivity and now I when I login, CPanel isn't loaded fully and as a result, I can't open anything etc.