Hard to say on transplanting. In my climate I would expect it to be in a 3 to 5 gallon size if it were 2+ years old. I transplant smaller plumeria every year to every other year depending on how fast they grow.

Full sun and a fertilizer (Read the other posts for info on fertilizers people like if you want to get technical). One well published author says use balanced fertilizers others on this forum say something else.

I say use what's available to you and experiment to find your best results.