Troubles with my MacBook air applications bar

Good morning

I am a MacBook Air fairly new user, if someone can help me with my issue I would really appreciate.

I am having trouble saving an excel file, I am "saving as" then when the window comes up i can click on the save or cancel option as the application tool bar in on the bottom of the screen is blocking the bottom of the window. I can not hide or unhide the bar or make smaller the " save us" window, now I can't even close the file as it is in a middle of a command that I ask and I can't cancel or save because of the blockage by the bar.