H1 Transfer question, here is

H1 Transfer question, here is my case, please help.

Dear Everyone,

I got a job offer for 1.4 years and that company agrees to sponsor me H1 visa. But I still need to find a job after that 1.4 years. My questions is: will the H1 transfer very easy comparing to a new application to H1. What kind of side effects I will get.

Also, is it probable that a company sponsor me even before I start my job there? (I suppose H1 transfer is the case here. I have to get H1 transferred before starting the job)

Thanks a lot!
Carol