have you ever been there (here) or have you ever been TO there (here)?
I've never been to (somewhere) - it is correct, as I understand. Is it still correct I've never been in (somewhere)?
And how to ask it in a question?

Question

Answer

To me 'I've never been in Russia' is not incorrect, but it is not as natural as 'I've never been to Russia'. 
No 'to' in the question. Have you ever been here? What about Australia? Have you ever been there?

Non perdere l'opportunità di imparare una lingua comodamente da casa tua. Esplora la nostra selezione di insegnanti di lingue esperti e iscriviti subito alla tua prima lezione!