Playing games on android

Ive downloaded a game to my phone but its not showing it so that i can play.

In order for us to provide better support, we need to see the log generated by yuzu. This guide will walk you through how you can obtain the log file: Getting Log Files - yuzu

Can someone please help me?

You need to dump your keys from your own Switch to be able to run the games: Quickstart Guide - yuzu

How do i do that without a switch?

You can’t, owning a Switch is mandatory.