Keywords

As @Jill_C says, Adobe suggests keywords, but not all the suggested keywords are relevant to your picture. You need to pick those that fit, add your own, order correctly, and submit for moderation.

If you have prefilled keywords, those were present in the EXIF data of your picture file. Those keywords come either from you or from the software you're using. There also, you will want to check the keywords and keep only the relevant ones.

Adobe doesn't add keywords. They show a list of suggested keywords, but those don't populate into the Keyword box unless you Click on the "+" button next to the keyword or "add all".  To delete unwanted keywords, click on "Reordering tool" button just above the keywording box, then you can delete individual keywords. You can also change the order that they appear by dragging them up or down, or press the up arrow icon to move them to the top of press the "x" to delete them altogether.