Question1:Why at frist taxi driver  passing him did't  take notice of his signaling?

Question2:How do you understand " I knew that I shouldn't have gotten into the taxi without understanding what the driver had said to me"?

I am used to taking a bus home,but last night it was raining and I decided to take a taxi.I stood on the sidewalk signaling to each cab that passed.I expected each one to stop,but none would. Then I remembered that it was the time of day when one group of taxi drivers stopped and another began to work. I began to wish that I hadn't had the idea of getting a taxi in the first place. I was soaking wet.I set my briefcase down and took off my hat for a minute to pour out the water that had collected in the brim.

At the moment ,a taxi stopped in front of me and the driver said something that I didn't understand.I quickly jumped in and sat down."Where do you want to go?"he asked me.I gave him my address. "That's uptown,sir,"he said."I'm going downtown.I told you that.I'm off duty now.I was going to pick you up if you were going my way."By this time,it was raining harder. Cars were stopped behind the taxi.Their horns were beginning to demand that we move. I wish I had known what to do !I felt like in sitting that the taxi drive take me home .But at the same time ,I knew that I shouldn't have gotten into the taxi without understanding what the driver had said to me.Two more blasts from somebody's horn made the driver demand that I make up my mind.I got out,although I didn't want to.But my story does have a happy ending.As I stood dripping on the sidewalk,feeling sorry for myself and trying to decide what to do next,a friend of mine drove up and offered me a ride home.I assured you he didn't have to insist. I hopped in and away we went.