Yes, one can build a wheel with nothing but a spoke wrench and a bike or fork to mount it on. Can YOU build a dependable wheel, round, true and properly tensioned, with only those items and no previous experience? Perhaps but the odds are against you.
That's not a challenge, just a fact. I think you are better off having a wheel built - unless you can find a quality prebuilt one that has the same hub as you already own.