あなたの家にWi-Fiありますか？って英語でなんて言うの？

"Do you have access to wifi at home?" If you ask someone if they have "access" to wifi at their home, it means: "Are you able to connect/login to wifi at home?" or "Do you have wifi at home?"

If you want to find out if someone has internet at home, you can ask them, 'Do you have wi-fi at home?'

If you want to ask if you can use their internet, you can ask them, 'Can I use your internet?'

The two questions you see provided above are excellent ways to ask your friend if they have WiFi at their home. In the first sentence you will see the word available. This means something is ready to be used. This word is commonly used in both formal and informal settings. It will make a very useful part of your vocabulary.

Do you have wi-fi?
Do you have wi-fi at home?
Do you have wi-fi in your house?
Have you got wi-fi?
Have you got wi-fi at home?
Have you got wi-fi in your house?

Native speakers will say like this: “Is there Wi-fi at your house?”.
There are lots of other ways to say it, but this one is the most accurate and most commonly used.
Here is an example on how to use this in a conversation:
A: Hey, do you have Wi-fi at home?
B: Yes, of course!
A: Can I please have the password?
B: Sure, it's abc123.
A: Thank you!