for the moment, the way is alt+enter

that will go full screen. qb64 is being very actively developed, but the goal is not only to add new features to qbasic, the first goal is to make it as easy as it can be to run un-edited qbasic programs.

in the future, there should be more of those that run without editing. as for the console window that pops up, galleon did mention that he was working on that, but i don't know in which future version it will be taken care of.