1. Yes. But to improve it drop OF as this is not needed. And you could use the word decide instead of choose. Also " wear TO the meeting"
2.Add AMOUNT OF after this. As you are being specific in the amount of money you're talking about.
3. The best way to learn English, is to translate it.
4. People = plural person= one. I'm sure you wish to check that there is no one at all left = people, Not just one particular person. Let's check if there are any people left on the train.
5. What kind of car WOULD you LIKE for your birthday. A bit more polite. Or What kind of car do you want for your birthday. Drop " want to get".