One of your mistakes is that you first create $X which looks like it's a reference to array, but then try to print @X[1], which is an element of @X which is different to $X. See this example:

$ perl -d -e 1
  DB<1> $X = [ 1 .. 10 ]; # create a reference to an anonymous array
  DB<2> x $X # print the array by its reference
0  ARRAY(0x9a45510)
   0  1
   1  2
   2  3
   3  4
   4  5
   5  6
   6  7
   7  8
   8  9
   9  10
  DB<3> @X = ( 2 .. 20 ); # create an array       
  DB<4> x @X # display the array
0  2
1  3
2  4
3  5
4  6
5  7
6  8
7  9
8  10
9  11
10  12
11  13
12  14
13  15
14  16
15  17
16  18
17  19
18  20 
  DB<5> x @X[1] # display an element of the array
0  3
  DB<6> x $X->[1] # display an element of the anonymous array by its r
+eference
0  2
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See perlreftut for more information.