Depends upon the size of your container and how you "set it on the site".
First lets correct a couple of mis-statements. Generally (exceptions are the rule), structures exceeding 120 sq ft require a permit. But you are not limited to 10 x 12. Nor will need a 40' container (good luck pulling a 40' doggy up our twisty narrow canyon roads) The most common container size is 8 x 20.
Containers are self supporting, so a foundation is not needed if you have a compacted well drained flat 9 x 21 pad. Unless you plan to dig footings deeper than 18" you will not need a permit.
Buy a 8' x 20 in good shape.
Find a spot more than 5' from proprety line and 10' from any other stucture or oak tree.
Open up one end of the container by cutting out 2 @ 5'w 6'h window from the side walls. Frame out a 8'ft door. You now have a 8 x 15 shed with a 8x 5 porch.
Set it atop a few scoops of compacted, contained 3/4 gravel.
Viola! you are now code compliant for under $3K.
Not a do-it-your-self-er (or own a tricky lot or want more SQ FT)? Topanga has local outfit that will set you up (for a price) and pull permits if needed.