we must find out how many hydrates are present in the sample
There is one hydrate present - copper sulfate.
Apart from atrocities you do to the naming of substances and things you calculate, your approach is correct. I haven't checked the numbers, but the logic behind is correct. You should not round down intermediate results when using them for calculations (reporting them as rounded is correct though).
Next question asks to determine the number of hydrates in the sample.
Number of water molecules per salt molecule.
Moles of CuSO4 = Cu-63.55g/mol + S-32.07g/mol + O-16.00(4) = 159.62g/mol.
Moles of H2O = H-1.01(2) + 16.00 = 18.02 g/mol
It is not "Moles", it is molar mass.
You are right final answer should be around 5. It rarely is exactly 5, although below 4 seems to me a little bit too low.
Think about possible sources of experimental errors. What will happen if the sulfate after roasting is not completely anhydrous?