are physical copies available anywhere?

At this time Hello World is entirely digital, unless you print it out!  (The booklet prints to a sheaf of ordinary letter-sized paper folded over in half when you print it using the "Booklet" settings on most printers, everything else is presented in letter-size landscape-oriented).

In the space of a few weeks though, we will be kickstarting for Zinequest 2 a publication called Pocket World that will feature many of the same themes as Hello, World!  Things depend somewhat on how well that does but it could be a test run for an eventual physical version of Hello, World.  More information soon to follow in this space!