A GMail account is a free Email account through Google Services.
When you create a GMail account, you are creating a Google Account.
That is OK. It's all free. Just be aware that Google is getting very good at collecting user's information so that they can make money through advertisers.
First, create a Gmail account. https://support.google.com/mail/answer/56256?hl=en
Your Gmail account will allow you to connect with various Google Services. As you go through signing up and 'accept' the terms and condition, you can decline any offers to set you up with other services, (and always can come back and add them later).
An introduction to what a Google Account is at this link: https://support.google.com/accounts/answer/27439?hl=en&ref_topic=2373943
Answers to common questions about your GMail account, are here.
There is a Google Calendar, also free, and other helpful software. Personally, I am skeptical about giving too much of my information to a free, web-based service, so I consider other ways to stay organized.
Hope this helps.