Newbie needing help with debounce errors in arduino
In the description of Debounce, you'll find the hint that this library is outdated and no longer maintained.

Its successors, Bounce1 and, more recently, Bounce2 are available from a github repository by Thomas Fredericks, Bounce-Arduino-Wiring.

Instead of simply downloading and unzipping the archive to ${HOME}/sketchbook/libraries, you might want to consider that this is the right moment to get familiar with git repositories as an easily updatable source for third-party libraries.

Supposed that you're on a GNU/Linux system with git installed, you would

cd /${HOME}/sketchbook/libraries
git clone https://github.com/thomasfredericks/Bounce-Arduino-Wiring.git


to obtain a clone of the necessary data.

If the name of the directory of the library contains dashes (-), you'll have to change this name: remove the dashes or replace them with underscores (_). Names with dashes aren't valid! 

Once in a while, you would change to the directory of the respective library and simply run git pull to update your local copy to the latest version of the repository.