My phone is unlocked, but I don't remember pin code. Recover from Google somehow? There's plenty of directions for those who forget their pin code and can't unlock their phone, but there's no explanation for those who have their phone UNLOCKED, but don't remember their pin code to change it.

I can use my phone right now, but I don't remember my pin. That's why once it's off or the screen is locked, which will happen at night, I suppose, I won't be able to access it anymore without wiping the data.

Is there an easier way for me to deal with the problem?
I think you can turn screen timeout off, if possible (may vary by OEM).
Most times, Google has no control of your phone lock, as far as I know.