Template (C++) - not sure if correct

I'm a student and I'm doing a static library for arrays in C++, so I don't have to rewrite code every time during lessons.

I'm at second year in a secondary school so I'm not an expert. I want my code to be compatible with all type (int, float, ecc.) but I'm having some trouble.

Can you give a look at my code?

// slarray.h
#if !defined _SLARRAY_
#define _SLARRAY_

template <typename Tipo> class Array {
  public:
    void inserisci();
    void visualizza();
    void copia(Tipo*);
    Array(short);
    ~Array();
  private:
    Tipo* ary;
    short* siz;
};

#endif

// slarray.cpp   
#include <iostream>
#include "slarray.h"

unsigned short i;
unsigned short j;

template <typename Tipo> void Array<Tipo>::inserisci() {
  for (i = 0; i < *siz; i++) {
    std::cout << i << ": ";
    std::cin  >> ary[i];
  }
}
template <typename Tipo> void Array<Tipo>::visualizza() {
  for (i = 0; i < *siz; i++) {
    std::cout << ary[i] << " ";
  }
}
template <typename Tipo> void Array<Tipo>::copia(Tipo* arycpy) {
  for (i = 0; i < *siz; i++) {
    *(arycpy + i) = ary[i];
  }
}
template <typename Tipo> Array<Tipo>::Array(short n) {
  siz = new short;
  *siz = n;
  ary = new Tipo[n];
}
template <typename Tipo> Array<Tipo>::~Array() {
  delete[] ary;
  delete siz;
}

The code gives me errors when I try to inizialize the class with:

Array <int> vct(5);

Template implementations need to be visible to translation units that specialize them.

Move the implementations to the header file from the cpp.

A few other notes:

unsigned short i;unsigned short j; should be made local, there's no need to have them as global variables.
Macros starting with _ followed by a capital letter are reserved, so _SLARRAY_ is illegal, rename it.
Implement an assignment operator and copy constructor, otherwise all copying will be shallow.

I'm assuming you can't use std, otherwise you are aware that containers already exist there, right?