Hi there,
TranslatePress saves translations at the string level, while WPML saves at the post level. We don’t create new pages like WPML, but every existing page in your site will have a “translated version”, even if it’s strings are translated or not.
That being said, you can’t migrate your translations to WPML. ?All the translations done with TranslatePress are saved string by string in the wp_trp_* tables from your database. The closest thing to a migration is you opening those tables and copying the text.
To completely remove TranslatePress you also need to manually delete those tables from your database (those will remain even if you uninstall the plugin).
Best regards,
Cristian