Presumably you are needing to add translations to the Field Labels, which will be in sys_documentation.list. If you need to add translations to choice values, these will be in sys_choice.list
In both tables, you will find an entry for the value(s) you just created in English. Open each record, change the Language to FR and translate "Label, Plural, Help & Hint" for sys_documentation (field labels) or "Label and Hint" for sys_choice (Choice Values).
Additional Note:
For many of the other fields, such as those which are of type Translated Field / Name (deprecated), Translated Text or Translated HTML, the easiest way to translate is to navigate to the page containing the values to be translated, switch your instance to the target language and translate said value and UPDATE or SAVE.
All three field types will automatically create a new entry in the appropriate table. Once created, you can go find the new entry and use it as a template to be used to create bulk upload spreadsheets. Important note though, the OOTB transforms for sys_translated_text and sys_translated are problematic if the coalesce values are blank so watch this closely.
Oh, one other thing. If you need to translate popup messages, conditional messages which show up based upon a value (e.g. ui macros, client scripts, catalog client scripts, etc) you will first need to ensure you are enumerating your messages in sys_ui_message with a key value (which you will use in the code itself) and the message you want to show up in the UI. Then, in your code, you would use either gs.getMessage{} if you need a glide record or ${} if you don't (such as for catalog client scripts). When you are done, you will have one message record for each language for a single message, as in the image shown below.
Hope this is helpful.
