It would be correct to say that it was a Portugese Colony for close to 500 years.
No, it is not correct to say "had went." The correct usage is "had gone." "Went" is the past tense of "go," while "gone" is the past participle.
The correct phrase is "Have you ever had." This is the proper structure when forming questions using the present perfect tense.
Yo he estado en Espana (I have been in Spain) or, Yo he ido a Espana ( I have gone to Spain).
veinte y uno
No. Best is a better word for your intended purpose. It would be more correct to say greatest christmas ever than great
That is correct. You could also say: Tom has been unemployed for a month.
You have been travelling is correct. You would never say you have been on travelling, although for poetic emphasis you could say you have been travelling on.
"Has been" is correct, because "a block" is singular.
Venice Italy... don't ever say Spain
No. For plural, like are, you can say have been. For singular you would say has been.
No. You would say "It will be helpful" or "It would have been helpful."