Foreign marriage

I recently got married in Mexico to a Mexican national. He does not live or work in the US and I am self-employed but work in the US. His income this year was minimal and I was hoping to file MFJ to in order to take advantage of the greatest deduction. I have several questions - first, does this sound like the most sensible way to reduce what I owe? I am also the primary financial support for my stepson and have been for two years.  Second, if I do file MFJ, how do I procure an ITIN for my husband since he does not have an SSN? Third, would he still have to file US taxes, given that his income in 2022 will be under the minimum filing requirements? Thank you!