first time pond build

hi all going to build my first pond this sping any advice about hardware design plans ect would be great many thanks P
im planning to build a 12ft by 6ft by 4ft deep koi pond

Is this a koi pond or water garden?

its gonna be a koi pond

Any drawings would help.

im looking for ideas

well a dedicated koi pond is different than a garden pond with koi or other fish.

We can't help you if you don't help us.
If it were a rectangle it would be about 2150 U.S. gallons.
Pond surface 72 sq feet.
Suggested pump size 3232 gph
No-more than 6 koi. Here I'm suggesting that in a couple of years these fish would be over 20 inches,

i want this to look informal 2000gallons is about right i was toying with a kidney shaped pond

what size is an average koi pond?

There is no average for Koi ponds. I would say that less than a 1000 gallons is much harder to maintain. I have 2 ponds, joined by a stream that total 1500 gallons.