You can notice the gender of the noun from the article: le wifi, un wifi, or from the adjectives qualifying it, if any.
Easily, by the language making it an obligatory grammatical category for nouns. Grammar says there's concord in the language and some words have gender? Suddenly all nouns require gender for concord, regardless of whether it seems reasonable to you or not.
And so while "tavolo" in Italian is masculine, our table is feminine. And while our planète is feminine, Spanish's planeta ends with an A and is masculine.
English generally doesn't have genders on common words, except for cases like vehicles that can be found used as feminine (ship, car, …) [1], but that's fairly anecdotal.
[1] https://www.antidote.info/en/blog/reports/metaphorical-gende...
The closest idea to gender would probably be the idea of weak/strong vowels that while no longer codified, is what results in things like see/saw, run/ran, mouse/mice. IIRC Old English had a much stronger sense of these and conjugated many of their words in this way.
An example: Mouse -> Mice is valid. Moose -> Meese is not.
‘She’s a fine ship.’
Im not a native English speaker so I need to clarify my confusion. I take it WIFI is a noun. How is gender prescribed to a noun?