Repercussions re cancelling company sponsored school invite

So I got invited to a couple of orientations for CDL schooling last week. Recruiters are calling wanting a start date.
Sweet!!

Meanwhile the West Texas oil scene is beginning to blow up with work and now I'm a bit worried.
Unsweet!

**If I give a start date for orientation and two weeks later I'm offered my old job back what kind of repercussions can I expect when I cancel?**

**Worse (or better) yet, if I go through with orientation, begin training and while I'm on the road I get an offer I can't refuse what's gonna happen when I give them a notice?**

Obviously I'll be on the hook for school fees, but what, if anything, can they do to my DAC or chances to get back on the truckin horse again?

Either way, I WILL get into trucking as it's my best option for when oil goes bust again....and it WILL, but I don't want to burn any bridges along the way.

 

My bad, it's company sponsored schooling, not a private school.
Right now I'm totally committed to not going broke waiting on the oilfield to take a turn in the right direction.
Family 1st, career 2nd.

Company school I'm considering is free with a 1-year contract.
The newest west texas find doesn't seem to be waiting on Trump. If it's as big as they say it is, they'll test the caca out of it regardless of the ppb of oil.

 

Good point. Edited.

Issue is making sure I don't get any bad feedback for cancelling out on a company sponsored school after setting a date or leaving before training is finished.

I'm not trying to make waves with the lifers here but when I've got someone offering me $600+/day to return to my old job it's hard not to put this career on hold until I can catch up on some bills. Maybe I can afford private school at that point.