I think it depends on the company that hires you. I have a home infusion job (which I LOVE by the way lol!), and I was trained. I already had IV experience from an ambulatory endo job but still needed training for ports, PICCs, midlines, Broviacs, blood draws, infusions, dressing changes, etc. As you know, peripheral IV insertions is on the job training. The more you do, the better you get. I guess just like everything else, really! Good Luck to you!
Where I worked, they trained nurses who were new to infusion.