Be prepared for hate if you're healing, for some people the healer is always at fault.

Your best bet is to join a guild that does fairly regular dungeon runs and seek advice from the more experienced healers. Successful healing strategies can be very group-specific and trying to learn while pugging can be challenging.

Are you on the PC/NA platform? If so, we can help you out in Lone Wolf Help. We run Group Dungeons often and have a scheduled Monday Night run, and we are not in the habit of blaming anyone for deaths and wipes and the like. We usually laugh at ourselves, dust our selves off and try again. Like last night, I was doing some stupid things with a Boss and got killed a few times. I chided the healer, but took the blame myself for what happened.

If your on that platform and want to join up, send me an email in game. We have a couple of good healers that would mentor you. @wayfarerx is one of them (the same one I chided last night in fact, he always keeps me alive unless I am doing something dumb)

If you want a good experience in this game with group play, DO NOT PUG AS A START-UP-HEALER - get friends, get into social guilds and get more friends - run with your friends, and be helpful in general because it pays off.

Socializing is part of getting success in endgame of this game, without that you will be missing a lot. Your network of guilds and friends list will determine how good of an experience you will get as a healer.

Also as a new healer, you should focus on levelling skill lines and skills up. You will need restoration staff and destruction staff levelled for pve healing.

Here is a good guide with input from the community on Healing

https://forums.elderscrollsonline.com/en/discussion/108629/tips-for-healers/p1

Its an older guide, and some skills have changed a little, however the Theory is still the same