Answer 1

[1] Go to the section with a thunder bolt, click on the + button and select a language (weapon).

[2] Go to the opponents profile, click on the 3 vertical dots at the top right corner and select challenge.

[3] On your activity feed, you'll see some completed challenges by members, click on a profile you'll be given 2 options.
{view profile} {challenge}
click on challenge.

Answer 2

RTFM 😊

Answer 3

in the bottom left theres a tab that says “play” press it then press the green plus sign at the bottom and choose what language you want to use.