[kunitokotachi]

I am very confused about your title "sentence structure in kanji." Kanji is one of the three systems of writings in Japanese. Many of the hiragana words can be written in kanji form. However, I wouldn't worry about the kanji until you have become more proficient in basic Japanese. After that you could gradually start learning kanji. Just make sure you don't start with difficult kanji such as 綺麗 before you learn kanji such as 山.