Hi! I think this video should be helpful for that. Please ask more in its comments section if you still have questions. 🙂 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MbiOD8jOiTQ.htmlsi=zpdMe_d9ZhWkHcxG
Splendor Jades are in the Spirit Forest event shop that comes around once a month, I feel pretty sure. I haven’t played in months though, so I could be wrong. Best of luck.
I would definitely wait until you’ve upgraded a couple times first before evolving. Also, the number of shards you can feed the evolve process hugely impacts the boost in your stats, so try to gather those first too.