Settings, Apps, select apps to be deleted, then Clear Cache, Clear Data, Force Stop, Uninstall. Only apps you've installed yourself can be deleted in that way.
From time to time, clear your Cached Data in Settings, Storage.
As you have discovered, using low-storage devices can be frustratingly difficult.
Welcome to Android Central! If the Microsoft apps were preinstalled, chances are you can't remove them unless you root the phone. You can probably Disable them in Settings>Apps, which can reduce their size since it forces them to revert to the smaller factory-installed version (updates are typically larger).