Where can I find the speed of my Wi-Fi?

Which Wi-Fi router version do you have? it’ll usually be IEEE 802.11[letters].

That’s part of the limit.

The other part of the limit is which iPad you have. Older iPad will have older Wi-Fi versions.

Wi-Fi IEEE 802.11 max speed info:

Above-listed speeds are best case, your speeds can be and usually are somewhat lower.

There are also downloadable apps available in the app store which seek to measure Wi-Fi speed.

Using a website such as mentioned in the reply above also works, and will measure the speed of the slowest part of your entire connection, which can be the iPad itself and its local Wi-Fi hardware, the Wi-Fi router inclusive of any local Wi-Fi interference or signal degradation, and the ISP connection.

If you mean that you want to see what speed your actual performance on your wi-fi is, one option is: https://www.speedtest.net/