Windows 10 interface has completely change - Please help

Hi
Not sure if this is the right area to post this as this is my fist time using the forums. I have not used my laptop in a couple of days and believe that in that time, it has auto updated and now the interface that I was used to (and loved) has completely changed. Previously, my Windows 10 OS looked similar to that of Windows 7; since the update is has become almost unrecognisable and unusable.
When I turn on and log in, instead of the usual desktop and subsequent icons; I get the following screen:



As you can see, it is like a permanently pinned start bar is open and I am unable to remove Cortana from the task bar.

Should I want to use the previously known 'All Programs' on the start menu, this is what I am presented with:



If I open any program such as Firefox, Spotify, Netflix etc. there is now 'X' or '_' in the top right corner and these have to be accessed by right clicking on the chosen program via the task bar. Similar, I unable to get back within Settings or any other Windows screen and have to use the back button in the bottom left of the screen via the task bar. Has anyone else come across this issue/interface of Windows and do you know how to revert back to the much loved previous interface?

I have posted my version of Windows 10 below, if it helps?

You have the device on 'Tablet Mode'.

Turn On or Off Tablet Mode in Windows 10 Windows 10 General Tips Tutorials

Try Tablet Mode on/off

or

Your Windows version is slighty out of date for 1603 as the latest OS build is 14393.1198
The ltest version is the creators update currently at ver 1703 Build 15063.296

To remedy your sart menu:

Goto settings, Personalization, Start and turn off "Use Start Full Screen"

I dont see an image for your X in the right corner of application?
I can only assume that you mean a checkbox !
To remedy this, goto explorer, View, and untick "Item Check Boxes"

HTH