Hello @adivj95
1. For Bulk import of assets, we can use the following option:
https://experienceleague.adobe.com/docs/experience-manager-learn/cloud-service/migration/bulk-import...
2. For Content Fragment Creation, we can write our own script. It would also allow us to create relevant folders and name convention.
3. For associating asset with CF, please check if OOTB metadata import/export helps.
https://experienceleague.adobe.com/docs/experience-manager-learn/assets/metadata/metadata-import-exp...
Also, you can combine 2 & 3 in a single script. Then you would be able to define proper associations based on naming conventions easily.
Aanchal Sikka