How do I emulate PS2 on my phone?

I downloaded some PS2 emulateurs from Play store but they all make me watch 4 ads every time I click on something and I think I also got viruses on my Android
Thank you smartphone culture

Despite having a long history with pc's, I've never really used smartphones.

I just got my first Android phone so I could emulate games on a train.
The experience has been mostly horrible, every app being riddled with ads. I tried a few PS2 emulators and after that my web browser has been opening casino sites and shit even on sites that shouldn't do that.
Like, I click an archive.org link and it takes me to a fuckin casino. My web browser is DuckDuckGo.
Being new to Android I have no idea how to scan and fix malware issues. I'd rather not reset to manufacturer settings.