So, i'm planning to buy a new xbox series S, i live in belarus, and i wanted to ask if my...

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.
I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today KILLERMID

Yes, your dad can purchase content with their USA payment method in your account (please note that you need to set your account region to USA if you're going to purchase basically everything there)

But you can experience some issues with the online functionality. Due to xbox live network is not available in Belarus
https://www.xbox.com/regions

Not the One. I plan on buying a Series S, but wanted to make sure that everything I have on my Series X will be able to be played on the S as well.

My current console is a Xbox one S and I’m planning to buy a Xbox series S

If the new xbox did come out this year i would not buy it; not after the RROD problem with the early 360's. I plan on wating untill the 2nd generation of the new Xbox before i buy this time. I plan on playing my 360 for at least 2 to 3 more years; I'm in
no rush to move on to a new system.

Basically the rundown is:

Xbox Series X:

Has a spot for discs

Has better graphics

More Expensive

Xbox Series S:

Entirely Digital (No spot for a disk)

Not as great graphics but still good

Less Expensive

So it's honestly up to you whether or not you want to get the better of the consoles, though the Xbox Series S would work for everything you would want it to.

If you still aren't sure you can look at this article I found explaining it more in-depth: https://www.techradar.com/news/xbox-series-x-vs-xbox-series-s-which-xbox-will-be-right-for-you

I wouldn't consider the Series S as the lesser of the two,

These consoles are much more like PC's in term's of spec and performance than previous generation consoles, and as with PC gaming, you get / buy or build a system to what resolution and refresh rate of what your TV / Monitor is being used,

"as an example",

"Your not going to buy an RTX 3090 for your PC at £/$1,500 just for the card, that's capable of gaming at 8K to only use it on a 1080p TV / Monitor, that's a huge waste of money."

The same can be said of these new consoles,

The Series S is designed and aimed at 1080p/1440p gaming as to why the spec's of the Series S aren't as high as the Series X, because if your not planning on gaming at 4K, you don't need all that extra power that the Series X offers as that is designed and
aimed at 4K gaming.

I have a 4K TV and a 4K Gaming Monitor so for me, I'm get the Series X,

However, If I was to only have a 1080p TV / Monitor and no plan's of upgrading to 4K, I would've been getting the Series S instead.

Xbox Series S it is. I just hope my Roxio Gamecap HD Pro would record it since it only connects with HDMI cable.