Where to apply for work, and quick visa question

Hello everyone, I hope that you are all doing well today. I would like to request some assistance.

I want to work and live in Japan, but I don't know which job board sites are in good standing.

So far I have seen two sties

Gajinpot, and jobsinjapan

Are these two sites good sites to apply to?

Does anyone have more sites I can use to apply, or is it better to apply to companies directly?

Lastly do companies help you with the visa process? from my understanding in order to get a work visa, it helps if you have a job offer

Thank you for your time

Sincerely

-Ghost_treat