Travel on B1 then change status to H1 B - Suggestions

Hi,

I’m looking for possible help.

My Employer applied H1 B petition for transfer (CAP Exempt – expired two years ago) one week back, the status still shows acceptance. Before applying H1 B petition I’m done with job interviews for couple of clients and I have an offer now with me. The client want me to join as soon as possible and I have B1/B2 VISA valid for few years, I never been to USA before but visited more than 5 other countries.

Now, I have following questions:

  1. Can I travel on B1/B2 VISA? – This VISA I got through my previous employer.

  2. During the port of entry or immigration, what kind of documents I need to show if I’m visiting my friend in USA?

  3. Once I’m in USA how can I change my status from B!/B2 to H1 B, is that possible?

  4. Will I face any issue when I go for H1 B stamping after few weeks?

  5. Can I visit Mexico or Canada for H1 B VISA stamping?

Thanks in advance, please advise.