Leave: a period of time when you are allowed to be away from work for a holiday/vacation or for a special reason 假期;休假
to take a month's paid/unpaid leave 帶薪╱不帶薪休假一個月
soldiers home on leave 回家休假的士兵
to be on maternity/study leave 休產假;脫產進修
How much annual leave do you get? 你們的年假有多長?

Fortnightly: happening once a fortnight 兩星期一次的(英式英語)

How often does the magazine come out?

Come out就是指刊物,書籍等的發行.
When is her new novel coming out? 她的新小說何時出版?

Do you have any order forms here so that I can get a subscription to the magazine?

Order form:訂貨單,訂購單
訂閱某物,可以說是get a subscription to sth,千萬要記得在雜志前的詞是to, 也可以說是"take out a subscription to sth".
取消訂閱就是"cancel your subscription",續訂"renew your subscription".