Hi there,
the first version is the latest production release v. 1.7.8. And is what we would recommend users download.
The second version is the next upcoming release v. 1.8 – we’re currently in alpha stage of public testing. We expect it to ‘go live’ within 2 weeks. You can see the changes it brings in our changelog:
https://generatepress.com/category/development/
Although we personally are using 1.8 on live sites i would suggest as a new user you may want to install that on a test site to see what the differences are.