Make the task bar visible at all times
I don't know any way to keep the taskbar visible all the time. But you can use a quick shortcuts to get this back.
Start + D = To view desktop. Alt+ Tab = To switch between apps quickly Alt+F4 = To close an app
Hope this may help.
Also check whether you taskbar auto hide option is not enabled. Right click on taskbar > Properties > Uncheck auto hide taskbar.