I need to play an easy as hell song to expand it, just adding drums etc, any ideas?

I dint play piano, so if you can help by noting it out would be awesome,

something cheesy like thomas the tank engine or something

Imagine. If you know the notes on piano, just learn it on guitar and tranfer over.
Beethoven's Piano Sonata No.14
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"death-metal is the best when its in the shape of a dildo and shoved in my ass"

Born to lose...
...live to Win
You could do "Clocks" by Coldplay. It's easier than you might think.
The slow part of Fur Elise, there's a thousand guitar tabs for it online.