Good job!I can understand you, but i still have some suggestion.
①我们可以少用塑料带,多用家里装满的袋子。The first part of the sentence is clear,But the second part I can't understand you well.Do you wanna say that we can use bags that not made of plastics?
②买好东西时,我们不要丢掉那个袋子而可以再次使用的。→买好东西时,我们不要丢掉袋子,(方便)再次使用。In this sentence,【方便】is not nessesary.大家都说的很好,这句话怎么说我们都可以理解 (*^▽^*)