We don't have any restrictions on where we can go, but seeing how it is peripheral, nurses would not be putting an IJ in, at least at my facility. Femoral would be done by physicians as well (we almost never do femoral lines in ER, EJ's are faster and less risky)
Brachial, and upper arm are common spots for ultrasound lines, from what I have seen.
And yeah, it is on the job training, you just have to be trained how to use the ultrasound machine before you can do it. And we usually offer a 1-2 hr inservice for staff every couple months