Just want email and office for personal use

Just want email and office for personal use

I am unclear as how to how I would have just a personal email (already do have it and love it) and get to use docs, notebook, workdrive etc. In other words mostly everything I had a google. I find gocs can be free with 5gb and so can mail with 5gb. Are they the same gb's. Why would I then pay $1 a month for 5gb when it's already free. Personally I would pay $1.25 for 10gb anyway but want to include office. I have nothing against paying and am looking at the $4 monthly option but don't understand it I really need it and get tired of buying things I don't need. 
Thank you for any help.