5. I will take some clothes to change and cleaning items.
我会带些换洗的衣服和洗漱用品。
还能这样说：
I will bring some spare clothing and cleaning items with me.
I am going to travel with some clothes and cleaning items.
应用解析：
item 项目，条款;一则;
item by item 逐条，逐项;
item on the agenda 议程项目
6. Pack some necessary medicine in your carry-on.
在行李箱内放些必备的药品。
还能这样说：
Bring some necessary medicine with you in your luggage.
Put some medicine which is in need in your luggage.
应用解析：
if necessary 如果必要的话;
be necessary 必须;有必要;
daily necessaries 日用必需品;
necessary condition 必要条件;
reasonable necessary 合理需要
7. Before traveling I need to buy a suitcase.
在旅行之前我需要买一个手提箱。
还能这样说：
I need a suitcase before I go to travel.
I should buy a suitcase for this travel.
应用解析：
live out of a suitcase 过居无定所的生活;在旅行中过日子
8. How much money will you have with you?
随身携带多少现金?
还能这样说：
How much money will you take?
How much cash will you equip with you?
谚语：
Money doesn't grow on trees.
挣钱是不容易的。