Employment Law Questions? Ask an Employment Lawyer.
Unfortunately, unless you can state that you are being treated differently specifically based on your race, religion, gender, age or disability, being treated differently does not create a cause of action or recourse with an employer.
As for the lack of training, regrettably there is no requirement that an employer train an employee in an area that they want them to work. The idea is that an employer would be motivated to do so, as a means of efficiency, but nothing in statutes mandates that an employer do so.
The employer certainly faces liability if your mistakes lead to any medical issues for others, but the law doesn't preemptively deal with that issue.
On these facts, without something more specifically directed at discrimination on the factors I mentioned, there isn't any recourse that you would have here.