A few things stick out at me: your riptide usage is low so that is something you could work on. If you don’t have a weak aura (or tell me when) to track it that could be useful. Weave with healing wave and only use healing surges if someone is in danger of dying (unless you have legendary bracers, but you don’t have those). Also on those logs you had too many healers by a mile, that will always suck for you as a resto shaman due to the nature of our mastery (healing more when targets are at low health). Get into the habit of spending tidal waves on healing waves in periods of low damage or when people need spot healing. Some fights are also not chain heal friendly, make sure your chain heals always can bounce if you use them otherwise spot heal instead using healing wave. Start with thses things and see how you get on.
I’d also suggest swapping out your mastery only trinket for an int stat stick from WQ’s as that will be better for you (or any other raid/dungeon ones you might have that could be useful).
Read through the guides at the top as well.
Poke me if you have more questions.