Please help me explain , why these sentences are ungrammatical. I underlined where I think the errors occur, and put my corrections in parenthesis,

Please help me explain, why these sentences are ungrammatical.

I underlined where I think the errors occur, and put my corrections in parenthesis, but I am having trouble with the grammatical terminology.

1. People living in the United States use fire flowers on the Fourth of July.
2. There are a lot of transportations on the road today. (cars)

3.   My cousin is having four cats. (has)

      4.   We felt the cats that she had on her house. (petted. in)

      5.   My parents will begin traveling all off the world. (over)

      6.   Marie's red new bicycle is a gift by her parents. (new red)