Hello,
1) Do you still get the 502 error or error from the WooZone plugin?
2) If you want to run the fresh WordPress installation you can use WordPress Database Reset plugin https://wordpress.org/plugins/wordpress-database-reset/ In case you don’t need demo content then just don’t install it, skip that step and install only necessary plugins via Appearance > Install plugins (XStore core and page builder are required, all the other plugins you may install depending on options you need)
Also, during demo content installation you can also manage what content you want to install, for example https://gyazo.com/7958fa40dc8458c4dd2c626939946d7b
3) Provide me screenshot of that popup for better understanding.
Regards