Weebly is a service designed specifically for those who don't know how to code, and don't want to hire a website builder. The builder itself is meant to be intuitive, however; if you need assistance with building your site we recommend you check out the Weebly help site here.
To do this, after you have already logged into your Weebly account, go to Settings at the top of the page.
Once in settings, go to the SEO section on the left hand side of the screen.
After that, click Save, and your done!
Congrats, you've successfully added Drift to your Weebly page. Feel free to celebrate in your own way!