how do i get to this homescreen?

The second screen does not show the Acrobat app. It is a web browser. Just go to the web page shown. Your Acrobat subscription will unlock some limited features, but Acrobat is a tool for Laptop and computer users. Chromebook is not. 

Not very much of Adobe runs on a chromebook

Minimum System requirements for Cloud Programs... scroll down and check each program
-http://helpx.adobe.com/creative-cloud/system-requirements.html

If the program you want to use won't work on a chrome book you will need to cancel

To Cancel https://helpx.adobe.com/manage-account/using/cancel-creative-cloud-subscription.html
-or Chat link https://helpx.adobe.com/contact/support.html

-click the chat icon at the bottom right of the page to open a chat session
-the chat icon looks like '3 dots inside a circle' at the lower right
-type AGENT into the chat window to connect directly to a person rather than the AI
.
Also - beware of answering anyone who sends you a private message
https://community.adobe.com/t5/community-help/avoid-phishing-3-easy-ways-to-identify-adobe-staff/td-p/10791730