The classes held in April aren't really classes. They are mainly school orientations, such as where and how to use the school library, and for the students to get to know each other.
ご質問ありがとうございます。
"The classes held in April aren't really classes."＝「4月にある授業は本当の授業ではありません。」
"They are mainly school orientations,"＝「それらは主に学校案内です。」
"such as where and how to use the school library, "＝「例えば、学校の図書館がどこにあり、どのように使うのか」
"and for the students to get to know each other."＝「そして生徒同士がお互い知り合うために。」
ご参考に。
April doesn't feel like school has started. It's mostly orientation for school.
Classes don't really start in April. It's mainly orientation.
ご質問ありがとうございます。
「4月はまだ授業が本格的ではない。学校案内とかがメイン。」は英語で「April doesn't feel like school has started. It's mostly orientation for school.」と言います。
また、別の短い言い方で「Classes don't really start in April. It's mainly orientation.」という風に言えます。
ご参考になれば幸いです。
アメリカ合衆国 
