Is this a question or something
They are abstract nouns because they don't state directly what they stand for but rather a vague meaning left to individual interpretation. Concrete nouns would be blatantly specific in their meaning with little room for individual interpretation of their meaning.
Okay this is what I would say: Hi! Thank you so much for your invite! I really appreciate it. Even though I would love to come to Europe I think it would be better for me to stay in my own country. I have no idea what Europe is like, I have school and a life here, and even though I would love to come visit I just could not really see myself living there. I hope you understand. Thanks!
Well yes since a prepositional phrase shows location
where: Downtown in Whoville.