how can i extend the visa b2? & if i can apply for a visa that allows me to work?

To extend a B-2 stay in the US, you would file Form I-539 Application to Extend/Change Nonimmigrant Status at the appropriate USCIS service center with filing fee of $455 prior to the expiration of your present allowed stay. Your fact situation does not contain enough information to assess how you may be eligible to work in the US. I suggest that you make an appointment with an immigration lawyer who can go over your possible options for employment. Due to the limitations of the Lawyers.com Forums, Alan Lee & Arthur Lee, Esqs.’ (the "Firm") participation in responding to questions posted herein does not constitute legal advice, nor legal representation of the person or entity posting a question. No Attorney/Client relationship is or shall be construed to be created hereby. The information provided herein by the Firm is general, and requires that the poster obtain specific legal advice from an attorney. The poster shall not rely upon the information provided herein as legal advice nor as the basis for making any decisions of legal consequence.