If you want to travel to any of the European Countries, which country seems easy to attain its Visa?

There is nothing like an easy or hard visa, whether in Europe or Asia. Your eligibility will largely depend on your status, travel history and the immigration experience from others in the same country as you. For example, you will need to convince the visa officer that you are capable of subsistence throughout your itinerary an that you will be willing to come back to Nigeria.

Though there are still some you can attain easily, like...

https://fornaij.com/question/which-european-country-visa-is-easiest-to-get-in-nigeria/