Basically, you are required to report all world wide income on your U.S. tax return. If and how it's taxed depends on to many factors to cover in one post. If you pay taxes to any foreign (non-U.S.) taxing authority, then that will be taken into account at tax filing time. The U.S. has tax treaties with many counties, and no two are the same.
As for the gift tax, there's an IRS Form 709 that's titled "Gift Tax Return". The name of that form can be misleading. There is no tax on any gift given in any one tax year, if that gift is less than $15,000.
As an immigrant, I don't see the form 709 applying to you based on the information provided thus far. However, it's perfectly possible you "may" have to deal with a FBAR for foreign bank accounts and other assets you own or owned in 2021. No sense going into all that now though. I would recommend you get started on your 2021 taxes as soon as possible after Dec 31, 2021. I would also recommned you *NOT* use the online version of the program for your 2021 taxes, but instead use the CD version that you physically install on your computer. The CD version (in my personal opinion) is more more user friendly and versatile and will allow you to do things with your 2021 tax return that just flat out may not be possible to do with the online version.
So upon packing up to leave for the U.S., make absolutely certain you've got all paperwork associated with any non-U.S. bank accounts and other things you own or owned in 2021. Chances are you will need it for correct tax reporting on your 2021 tax return.
Finally, if you don't yet have a social security number, that needs to be the number one item on your list of "things to do" upon your arrival in the U.S. It generally takes 6 weeks on average from the date you apply, to get your social security card. But with all this COVID stuff it could take considerably longer. So apply for your SSN as soon as possible upon your arrival in the U.S. (Most employers will not hire you until you have both your social security card and your green card in your physical possession.)
We went through all this when we helped relatives immigrate from the Philippines. So I'm comfortable in saying that I've been there, done that, got the T-Shirt. 🙂
