Every noun is masculine, feminine, or neuter. This affects the endings of adjectives and verbs used with them.
Russian grammar is famous for its "cases," where the endings of words change depending on their role in a sentence.
Unlike English, Russian doesn't use "a" or "the." To say "a book" or "the book," you just say книга ( kniga ).
These look familiar but sound different: В = V (like Valentine) Н = N (like No) Р = R (rolled like in Spanish) Х = H (like a raspy "h" in loch)