As for your page - Unless you have Thrive Architect you cannot remove your sites header. With Thrive Architect you can build a landing page that you can custom create any way you want.

However you can choose landing Page beside the editor in your wordpress dashboard for your thank page and that will remove your sites menu from displaying but it will still ahve your sites header.

Your confirmation page and Aweber - go into your Aweber account - click on Sign Up Forms - as you create your sign-up form or if you’ve already created it click on the sign up form and in step 2 of creating your form you will see where it says Thank You Page, here is where you add the link to your confirmation page, your thank you page.

If you are using Thrive themes and Thrive leads - go into the members area of thrive and they will answer your questions, click on the supprt form for your theme. You can also check out the video tutorials as well.

Also you can live chat with Aweber and they will guide you through things.

Many themes, as Thrive, Divi themes have an option on the right side of the page to change "default sidebar" to "no sidebar" and create a blank page. I also use an ultimate landing page plugin which is free of charge.

don't you just embed your code from aweber ( the thank you page)?
and add more from thrive if you want to add more value for your visitors?
phil

I use mailer-lite not to familiar with Aweber