US Immigration from Nigeria

I am confused and stuck on this question,

"At which USCIS office will the beneficiary apply for adjustment of status to lawful permanent resident?"

What exactly does that mean? Is it asking about an office in the states or Nigeria? If it's in the state, what are the best options?

So I am currently filling out the online application to have my husband come over... hopefully. But I am currently stuck on the employment section for him. He is self employed, a driver actually, like uber or taxi. He doesn't drive for a specific company. Will him being self employed mess up our chance of the first step being approved? Will they ask for taxes on his part or documents showing proof of employment?

Is it true that US citizen married to immigrants won't get stimulus.. https://www.nbcnews.com/news/latino/u-s-citizens-immigrant-spouses-sue-get-coronavirus-checks-they-n1205236

Good day to all of you. I'm so so confused about what happens when case has shown "ready" at embassy. Will embassy contact fiance with information on how to proceed? I hear of packet 3. Will he receive this from embassy? He has not been contacted yet. please, help.

My social security card has my maiden name and valid to work only with DHS authorization only. My ead has my married name.

I just got a job offer but they said I need to change the name on my ssn before I can proceed.

I called SS office and they said I have to send in my original documents to change the name.

Please, who has done it before and how safe is it?

I need an advise.