Definitely NOT less than 5K miles man; remember you have almost 10L in there, which is basically twice the amount of normal engines. And no need to change it now either; wait until 5K after the 1,200 service, which would be 6,200 miles. No need to throw your money away on oil changes. I also change it way before the recommended 15K miles, but mostly due to time (I put about 5K miles a year, coincidentally), but there's no need to go overboard due to the large oil capacity. If I drove the car more, I'd change it at 7,500 miles.
And yes, do a search for the DIY and also for the resetting of the computer. Good luck.