He went right into the school without paying any attention to me at all.
He walked right into the school and never looked back at me.
この場合、次のような言い方ができますよ。
ーHe went right into the school without paying any attention to me at all.
「彼は私に全く気にもせず学校に入っていってしまった」
without paying any attention to .. で「…を気にもかけず」
ーHe walked right into the school and never looked back at me.
「彼は彼は私の方を見もせず、学校に入って行った」
to look back で「振り返って見る」
ご参考まで！
カナダ 
