In short, you appear to have confused a hash reference (i.e., a reference to a hash) with a hash containing references. What you have here in the posted code is just a plain ol' hash (%hash) which holds a number of array references ([ ... ]).

To fix the last line, you need to treat the hash as a hash instead of trying to use it as a reference - change %hash->{$_}[1] to $hash{$_}[1] (and the same for [2]) and you should be good to go.

As for the error messages:

Using a hash as a reference is deprecated: You get this because you're trying to use an actual hash (not a hash reference) as if it were a reference. This used to be allowed, but isn't any more.

Global symbol "$hash" requires explicit package name: This one comes from trying to dereference the variable $hash, which doesn't exist. In Perl 5, %hash refers to the hash as a whole and $hash{x} refers to a single item within %hash, while $hash (with no {}) is an independent scalar. The sigil represents the part of the variable you're accessing, not the variable itself. (Note that this is different in Perl 6, where anything related to %hash is always accessed using the % sigil.)

Edit: Corrected typo. Had a %_ where it should have been $_.