Do I need to report every 3 months after getting my visa or after leaving Thailand?

It’s every 90 days, when talking visa’s you need to be exact

TM30 has to be done by owner of property for every night, it has to be done within 24 hours, and does not need an end date, so it will be valid to next TM30 when you stay at a different place, even for 1 night.

TM47 has to be done by you after being in the country for 90 consecutive days. You enter at day 1 so 89 days later it is day 90 and then the obligation to report exists.

You can report in a timeframe of a week before and after day 90.

The counter resets at the moment you report, so when you report early the second 90 day will arrive before day 180, which results in an extra need to report.

First TM47 after each entrance in the country has to be done in person at immigration office.

TM30 is within 24 hours of arrival. I think you mean the 90 Day report which is TM47. This is required if you stay 90 consecutive days in the country. It depends on entry dates and not visa approval dates.

The 90day starts counting every time you enter thailand. Tm30 has to be done within 24hours of entry, but the landlord/hotel/whatever does that not you