Hey Dan,
You should never be afraid to ask for help, there is usually someone here willing to step in and help.
More than likely that's how most of us got here!
Yes you can put an offset in your rim. If the rim wasn't centered when you started tightening the spokes it could easily have been set off to one side as there are several things you need watch all while trying to keep an even number of turns on the nipples.
Unfortunately the only way I know how to re-center the rim is to loosen all the spokes and start over.
I'm not saying it isn't possible, I just don't know how...
You shouldn't have to remove the whole Mary-Ann.
Just loosen the spokes enough to get the rim to move. and then keep measuring, tightening etc.
There were gobs of pages that popped up when I "Bing"ed -How to lace a motorcycle wheel-.
It sounds like you have the basics down, and the more you do the faster it seems to go.
The last wheel I did was a TTR125 one of the neighbor kids brought over. I used the forks of the bike as a stand, and tie wire (secured to the fork leg and triple clamp) as a guide.
I had to give the kid credit for trying. I also give you credit for diving in and having at it. I'm sure you already found out patience is a big part of this type of project.
Tuck\o/