A "Minecraft" licensed account bought with a new Microsoft account with email access (or migrated from Mojang to Microsoft, it´s the same thing)

After the purchase, you get a Minecraft Premium account (Java Edition)
This is a fully licensed Mojang account with Minecraft Premium (Java Edition) with mail access. You can change absolutely all data.
Security questions are set for each account. We installed them ourselves, so that you can change your mail to your own through the Mojang website without going to the mail that is tied to your account
In any case, secrets can be reset by mail, even if you do not know the answer to them. This is the advantage of an account with mail.

A new mail was registered for each Minecraft Premium account, which you can leave or
bind yours after the period of temporary blocking by the mojang security system of your IP address - 30 days or less, you cannot change mail more often, the mojang security system also temporarily blocks it, as well as when changing the IP address of the PC. We recommend that you leave this mail, first secure it as much as possible (bind your phone, change the secret, passwords, etc.).
Questions "when can I change my mail?" do not ask, each individually, does not depend on the seller. You are provided with clean, only registered mail, use it.
The mail you want to change to must not be registered on the site https://mojang.com/, as well as https://minecraft.net/

Change nickname, password, secret questions and mail here https://account.mojang.com/login
Skin change here https://my.minecraft.net/ru-ru/login/
Download the official launcher to play https://www.minecraft.net/ru-ru/download/