No way! First, you cannot work of any kind on B2 visa or VWP (ESTA), not even volunteer work. That's ONLY for tourism, visits. Furthermore, you cannot look for work or do anything which indicates any intent to remain - that's visa fraud. Such fraud is grounds for deportation (or mandatory departure at your expense) & permanent bar to reentry.
Only qualified employers can apply for any employment visa for their qualified foreign worker. Visas, if approved, are issued in your country of citizenship - where you would be interviewed as part of the application process.
H1-b visa application period currently closed. And is your master's or PhD in a STEM (science, technology, engineering, math) occupation? What specialized expertise do you hold beyond the master's degree? Without all that, you are not even qualified for H1-b. H2-b is seriously restricted as well.
Any employment visa is hard to get. Real US unemployment rate is 23.4%. For age 16-24, including recent grads, new entrants to US workforce, unemployment exceeds 53%. Even US engineers who graduated in the top 10% of their class from the most respected US engineering schools cannot find work. And engineering is supposedly the "hot ticket" for US jobs. LOL!