Once you have done with your Theme Editing and want to Publish your Site you can follow this guide.
1) Go to your Dashboard and click on Publish button present at the Top of Dashboard as shown in the image below.
Note: It is not necessary to always go to Dashboard for Publishing your Site. You can click on Publish button anywhere inside your Dashboard or Page Editor and follow below steps.
2) Step 1 will popup the Confirmation Window as shown in image below. Press Yes, Publish button to publish your site and if you want to stop process then press Close button as shown in image below.
3) Then Wait for the Process to Complete.
4) After the completion of process you will see the window as shown in image below. Click on Visit website button to see your Published Site.
Note: You can also View your Published website by Clicking on Site URL as shown in image below.