有两处错误,具体分析如下：
1.正确 Hello,everyone.—— 呼语
2.正确 The bus is leaving in a few minute.
—— in a few minute 表示将来的“几分钟后”,趋向动词的进行时态 is leaving 表示不久的将来,
3.部分有错误 So I'd just like go over some of our safe rules before we set off.
1）正确的讲法应该是 'd like to do,因此此处要改为 I'd just like to go over some of our safe rules；
2）后面的时间状语从句中用一般现在时态表示将来没有错误.
4.有错误 Firstly,you mustn't get out of the bus with my permission
—— you mustn't get out of the bus 意思是“你们绝对不能下车”,而 with my permission 却表示“在我的许可下”,前后矛盾,应该改为 without my permission（没有我的许可）.
5.补充部分也有两处错误：
1）If you get out of on your town 应该改为 If you get out of the bus on your town 或者 If you get out on your town.理由是 of 是介词,后面必须有宾语,因此必须补充宾语 the bus 或者干脆删除 of .
2）you all must stay closely to me.中的 stay 是表示状态的系动词,其后应该用形容词 close 作表语,需要改为 you all must stay close to me （把副词 closely 改为形容词 close）