Got my CoE, need advice for proper financial start

Edit: Sorry for double posting, Reddit was bugging out for me and pretending it didn't post it the first time.

I just got my certificate of eligibility for a 3 year engineer/humanities visa. I've lived in Japan on a working holiday visa for a year, then been in my home country for 5 months, and now moving back to Japan in November.

My situation right now:

– Age: 29 years old, single

– Profession: UI design and front-end web developer

– Pay: 3.6m salary, 16.8m from freelance contract in my home country

– Savings: 1.6m yen, 1.1 of which is in investments (index & stocks), but in my home currency.

How do I:

– Get my first bank account? I need an account that I can receive my freelance income on too. Which bank do you recommend for that?

– In my home country it was super easy to invest in stocks and funds (we have various apps and websites for that). What does that look like in Japan?

– Handle taxes? I plan to use Freee or MoneyForward and hire an accountant.

– Any other things I should be aware of? Resident tax, write-offs etc.

– Pension and health insurance? As I understand it, since I'm employed, I'm under 社会保険 and my pension is also under my job, which is good since that's a percentage of my lower pay, leaving my higher pay free from insurance and pension contributions.

Thank you in advance.

by intellectual_artist