Do I/will I need WiFi

Hi!

There will almost certainly be both connection possibilities: ethernet and WiFi. However, due to an unstable signal (especially if the router is distant or there are interferences), it is advisable to use an ethernet connection between the console and the
router.

You will probally need it for the first time you power up your console, but not to play games afterwards if i would guess, the Xbox One is the same right now.

I have no extra money in my budget unless I skip more meals than I do now! Someone has offered to buy a game console for me so lookin at which is theost economical!

I think the most likely answer would initially be yes. Just like how you needed internet for setting up the Xbox One, to get you going on the Series X (Scarlett) you'll probably need to set it up over the internet. There may be some offline capabilities
for the console but, like with whatever one else has commented, details are scare at the moment. I'd assume you'll most likely need internet for almost everything on the new console, it appears as if we're moving into a more heavy digital age for technological
innovation with both gaming and internet capabilities but, only time will tell!

I don't think it will be mandatory, but it will be necessary to sync your saved games and unlocked achievements.