If you have fifteen years pulling flatbed, you won’t require any driving training.
The only difference in pulling tanks and pulling freight that is strapped down is that you’ll want to slow below the posted speed recommendations for off ramps and curves. Slowing sooner in order to stop is also a must.
Liquid surge is no big deal if you handle your rig like a veteran driver. It’s really a matter of timing your shifting so as to reduce surge primarily for your comfort.
The only training required would be connecting the correct hoses to the correct outlet. And dealing with HazMat if you want to haul fuel or nasty chemicals.