Hello Oscar and thank you for your question,
The link provided by Rose will give you some information about Keyword planner, I wanted to give you a little additional data as well.
Keyword Planner allows you to manually upload keywords, up to 200 at a time if you are using the keyword generator, pull keyword suggestion from your URL or even select your product category from a drop down list. This will generate new words.
There is a second insight option is the one the would give you details on the original keywords and of course we always have inline suggestions for your existing keywords in the regular web interface.
You may also consider using our Excel add-on called Bing Ads Intelligence. You can download your existing account to get importable spreadsheets with information on your existing keywords and recommendations for new ones.
https://advertise.bingads.microsoft.com/en-us/resources/training/bing-ads-intelligence-tool