Now your code is completely messed up.
You have managed to get a playing.php in your "root" folder, but it's supposed to be in /web
That's the general structure how it should look like (only listed those files that had errors for you so far).
The new error says the playing.php isn't in the web subfolder but at the samPHPweb or whatever your root folder is called level alongside index.php
I have to ask: What version of SAM is installed on your computer / what is the version of the samPHPweb files in the Program Files folder of SAM?
Anything before 4.7 I think has a completely different structure and I got no idea if it's even possible to update that to make it PHP7 compatible.
No idea how that happened, but I'll pack a new zip file with all the files (except the config stuff) from my machine that works fine in PHP7.
I think that's the best way forward from here.