I intended to work outside.

Today, I was going to  to work outside,
but i left a laptop at my office so I can't work today. (In general, you can't start a sentence with "But")
I was planning a design for our website.
It was necessary to use the laptop for doing it.
Because there is nothing i can do , i'll buy a xmas present with my girlfriend now.
After that we'll watch movie called"In This Corner of the World".
Anyway, I've moved on from work into play.
It's OKAY sometimes,isn't it???

Good job! Only a few minor errors. I don't understand the last sentence though.

Yuji-san, this is good, clear English. I'm making a few corrections for punctuation. I'm also going to suggest some changes for style, to make the English sound more natural.

I intended to work outside.

Today, I'd planned on intended to working outside.
But i I left a my laptop at my office so I can't couldn't get any work done today.
I was planning on working on the design for our website.
It was necessary to use I needed the laptop for in order to doing it.
Because there is nothing i I can do , i I'll buy xmas present go Christmas shopping with my girlfriend now.
After that we'll watch movie called"In This Corner of the World".
Anyway, I've moved on from work into play.
It's OKAY sometimes, isn't it???

The pronoun "I" should always be written with a capital "i" (which is sort of the opposite of Japanese, isn't it?) Also, "Christmas" is a proper name, so it needs a capital "c" (or a capital "x" is you use the abbreviation "X-mas").

Of course it's okay to move on from work to play!