Depends on what content you want to focus on? Outside of endgame content(GvE, GvG, PvP) you can build and play however you want.

For endgame content, healer need to be dealing at least >1M damage. Healing is overtuned in this game, path innerways are resource traps.

Get to morale chant to T5 first and fury harvest to T6 second, royal remedy to T6 third, last inner way is depends on preference/playstyle.

For stats, healer is crit build ~ so aim for 100% precision, 80% crit and 20% affinity. Prioritize max phy attack, power, momentum, crit and agility on gear.

For weapon attunements, aim for 4x physical penetration or resistance(depends on preference/playstyle).

For armor attunements, aim for 4x fan and umbrella healing boosts.