being careless
The term 'estar desocupado' does not mean being careless in English. Instead, it translates to 'be unoccupied' or 'be idle'. It implies one is not busy and has no tasks or activities to do, not that one is not paying enough attention or showing enough care or concern, which would describe being careless.
Today I am free and can help with the project.
This phrase indicates that the speaker has no commitments for the day, allowing them to assist with a project.
My friends are free this weekend.
Here, the speaker is stating that their friends have no plans or obligations over the weekend.
If you are free, we can go to the movies.
In this sentence, the speaker suggests going to the movies contingent on the other person's availability.