A few questions... on I-864, husband employment, interview stage

[HtBlack 4]

Hi everyone, and thank you for all the help you've given me and keep giving me! Me and my husband (the USC) are getting things ready for the interview. We got our email notification with the documents we need, and he's getting ready his I-864 and his stepfather's.

Question 1 is, husband started working on January 5th. For the previous two years he hasn't worked so he doesn't really have any income from then to show, so we definitely need his stepfather to joint sponsor, right? Even if he was hired full-time by this company, and he will make more than 125% of the poverty guideline for our household of two, because he has just started working.

If it helps his case, we could ask for a letter from his employer? He works for a big company but maybe his supervisor or someone can help.

Then... his stepfather files taxes jointly with his wife, USC's mother; but she's not cosponsoring because stepfather makes enough on his own. So as far as I understood, we have to request the tax account transcripts from the IRS, but also submit stepfather's W2s because they display his personal income, whereas in the IRS transcripts there will be both's income accounted for. So question 2 is, is all this right? Apart from the transcripts and W2 (and if any, the other papers he submitted), does he need to mail me anything else? Do I need proof of his US citizenship, birth certificate copy or something? This is all so confusing.

And question 3... in our instructions they say not to mail them anything. I thought we were supposed to send them the I-864 and supporting documents! Do we just show them at the interview? It just says to do the online form, collect documents and notify them so we can schedule an interview. Also, can any of you share when you were given an interview, after you requested it? I would just like to know if we'll have to wait a month, or a week, or longer. I'm so nervous!

<3 thank you in advance!