Blue essence (BE) will vary depending on the account you have chosen to buy. Make sure you check the descriptions closely so you know exactly what you are buying. Some accounts will have just purely Blue Essence and others will have Champion Capsules you can open up and disenchant for your BE.
None of the accounts have been registered to any email address. When you receive your account you'll be able to register your own email address, change password. The account will be completely yours, it'll be like you made the account yourself!
Please check your junk mail folder if it has been longer than 10 minutes since you purchased! Alternately you can contact us on Discord (https://discord.gg/8TSY4ns) and we'll sort it out!
To see how much BE you'll need to be able to buy 20 Champions to start ranked you can check on our product pages under heading "How much BE will I need?"