And you will be presented with 2 choices:
1. Lookup blogspot URL (input the URL of your blogspot.com blog)
2. Lookup email (enter your email address if your blog is not hosted on Blogspot (custom domain) or can't remember blog URL or don't have a blog
The best way is good to update your Google account such as giving a mobilephone number to recover your account in case you don't have other means to recover your account in which case an SMS will be sent to your mobilephone.
how to recover blogspot user name,how to recover blogspot password,how to recover forget email id for blogspot