Modify the script

Im not fussing.
I need
1) From the site via API, the data is uploaded to the table - ready (on the justhost.ru files in .json format and .php. there I also upload the catalog in .txt from which the information is read what to upload)
2) So that this data is updated every 2 weeks - almost ready (The data entered into the table is not updated. The old data remains and the updated data is entered in the new rows in the table. It turns out that I have duplicate categories with different numbers in the table)