The spells are pretty straightforward, and if you’ve been WW-ing you most likely have a general feel for the melee/dps portion of stuff. Healing is mostly a mix of using the melee abilities and healing abilities.
The hard part early on is making sure you manage RenMist’s for maximum vivify cleave and getting used to that. Once you start learning fights you will know when to optimally set up ren mists to maximize how many you have out before the aoe/big dmg mechanics.
Learn when to SooMist and when not to. ( each tick of SooMist costs mana and to avoid the extra .5 gcd ) Talents will slightly change this but you really dont want to be sitting there SooMisting too much as there are better things you can be doing ( doing damage and regaining mana with BoK, getting more RenMists out with RSK, maintenance healing/set ups through Feyline/AT/RIsing mists if you took those )
Stay in melee but if you need to move quick due to mechanics it is okay, we are quite mobile and can dip in and out of melee if needed. But being out of melee makes the class tree auras, the interrupt, and entire melee portion of the toolkit (and it’s upgrades) useless. You will also be dumping melee mechanics on the ranged people if you stay in ranged. The anxiety of being in melee will subside after some time.
Play with your talents, understand them, and know what works in various situations/groups. The people who can optimize builds to the content they do will do better than people who just copy/paste the wowhead/world first builds.
Tons more info if you google “peak of serenity” ( itll be the first one that comes up ) I cant post links 
Check the articles for more information, and under advanced you can see more detailed info on RenMist, SooMist, RisingMist, Celestials, etc. The information is still relevant mostly to DF as far as the mechanics work. You can also join their discord and use the search function to get answers to frequently asked questions.