Need to reinstall my imported wordpress.com

This is my first time using www.remarpro.com and I’ve been having tons of issues.
Basically my posts uploaded using 2 different authors (an admin and an author I created) and all the media was uploaded twice with the 2 different authors and it give me an error about upload exceeded.

Basically I want to start from scratch uploading my wordpress.com to www.remarpro.com but I don’t know how to do that. I have thousands of images so it would take to long to delete them.

Need help thanks!