Head over to  https://www.avery.com/software/design-and-print/ 

1) Click the icon on the top of the page to log in, if this is your first time using Avery online click Create an account.

2) Once logged in click on Start your Design

3) On the next page search and select your label.

4) Once you have your label selected click on the blank label

5) Click on Import Data, then Start Import Merge 

6) Click on browse for file and select your .csv (to save a Google Sheets file as .CSV open the sheet and select File>Download>Comma Separated Values .csv)

Once uploaded you can check that the data looks correct, if so click next

7) From here you can drag over the fields you want to merge and arrange (we will have more options to center and style in a later step.)

8) Click next and Finish. From here you can center and style the sample merge to your liking. When done click Review and Print

9) Lastly, click on Get PDF to Print