Here are the combined sentences using "and" or "so that":

1. We should reuse water bottles and we shouldn't waste paper.
2. I’ll go by car so that I can take more luggage.

Now, let's combine the remaining sentences:

3. He decided to stay at home so that he could watch the match on TV.
4. They are studying English every day so that their English can improve.
5. We want to build a pool in the garden so that our children can swim in hot weather.
6. He bought his wife a car so that she doesn’t have to take the bus to work.
7. He went to bed early and the next day he felt better.
8. There was a big bang and the lights went out.
9. We should recycle trash so that we can reduce land pollution.
10. I’ll come home early so that I can have dinner with my parents.