I am assuming you want training on shooting from a concealed holster and by "class" you mean a shooting class, and not a classroom lecture or permitting class.
If that's the case, look no further - Sights and Trigger:
April 22nd, Concealed Carry, Steel City Gun Club, Bethlehem PAhttp://www.sightsand...igger.com/#2838
Joe is outstanding instructor that offers affordable classes with a reasonable round count. I will likely be there myself. I missed his CCW class the last two years.
Now, regarding cross draw v. strong side carry.
I currently carry a Taser in a cross draw holster at work. This is by policy and is one facet of a policy designed to help with weapon confusion - so you don't draw your pistol when you want a Taser and vise-versa. It is a much slower draw and is very uncomfortable.
Yes, with a cross draw rig the potential to muzzle sweep a body part or a partner/loved one standing to your support side during the drawstroke, especially during a high stress situation like the beginning of a gun fight, is one issue.
Another is weapon retention both in and out of a holster - you are able to get more leverage on the gun to keep it in your holster when it's on the strong side and if you are doing a speed-rock or draw to retention engagement, the pistol is vulnerable as you cross your body with it.
In my experience it's easier to conceal with a strong side carry (I carry just behind my hip at ~4:00). A cross draw would be carried in front of the weak side hip (so for me as a right hander that would be 10:00ish) which is harder to conceal.
Also, a drawstroke from a cross draw holster is a much bigger move. Much more obvious, a little slower, less effecient and you have more time off target than on until the completion of the presentation. With a strong side carry, I can point my muzzle in the general direction of my threat from the instant the muzzle clears my holster just by dropping my strong side elbow to my hip. With a cross draw, I have almost 90* of horizontal travel to complete before my muzzle is anywhere near my threat area.