Create an account from their website.
You simply create a new account
You go to minecraft.net and click on "get minecraft" on the right of the screen. Then it asks you create an account, go ahead and create one. After you create an account you can click buy to get the game then follow the on screen instructions to get the game.
Minecraft accounts are not things that can be opened. If you wanted to CREATE a minecraft account, go to minecraft.net, click the Register link in the top-right, and fill out the required info.
no, you can either create an account then buy or play demo on it.
you have to buy an account and create your own username and password
Technically no, you can create a mojang account for free but you won't be able to play minecraft Java.
You must buy another one or use Minecraft SP
Go to minecraft.net and click Register on the top right then you can create an account, remember you can't change your username after you make your account.
The only way that you can change your Minecraft e-mail would be to create a whole new account which would cost you $25.
I don't believe that you can rename yourself, you need to create the account name that you will keep for the rest of that account's existence.
create an entirely new minecraft account as it is most likely that you have run out of time on that account or if you did enjoy your play time maybe think about investing in the game itself.