my visa B2 is valid until 2022 but is on an expired passport, which I still have, so I would like to know if I can entry in usa without problems and stay longer than 90 days? Will i have to apply for an esta? thanks
It's no problem, just bring the both passports.
"If your visa is still valid you can travel to the United States with your two passports, as long as the visa is valid, not damaged, and is the appropriate type of visa required for your principal purpose of travel. " Visa Validity