How do I get out of the "Welcome Back" screen?
Solution 1:
In order to dismiss this dialog, you have to spend all of your badge points.
(I suggest stocking up on some Treasure consumables, as they are cheap and will help you get ahead in the early game.)
Solution 2:
If you cannot spend your badge points or are stuck on that screen just close and restart Steam.
Mine was stuck on the "Welcome Back!" screen as well, was not registering any of my clicks to spend the points, therefore I was stuck there. Restarting Steam worked for me!
Happy gaming!