Every DPS has jobs has its ‘easy’ and ‘hard’ parts, it’s ultimately personal perception on which is ‘easiest’. The best way to figure out which one is the best fit is to just try them all, even if it’s just looking at the abilities they get or whichever aesthetic you prefer.

In terms of healing I think it’s easy to feel like you’re not doing enough, especially at lower levels when you don’t have any options besides standard Cure and standard Stone / Aero. Even if you do find yourself in a situation where things are going wrong, I wouldn’t be too hard on yourself about it. Even if something happens that wipes the party, everyone makes mistakes ultimately. I’m sure that you aren’t in a situation where the party is consistently wiping from lack of healing. It feels terrible if you ever do get into that situation, but if it means anything it’s just that you might need a bit more practice, and every healer is like that when they’re starting out.

I’d recommend, try whichever things you like the look / sound of, and you’ll soon find the job that’s best for you. It might turn out White Mage is perfect for you, or maybe you’ll find that you enjoy one the DPS jobs much more. Whatever choice you make, I wouldn’t worry too much about having a ‘great’ performance if you haven’t had much practice. I don’t think it’s anything to be ashamed of even if you do fail, it just means that you need to keep working on it.