Read the official guides https://guides.emberjs.com/v2.7.0/ (no need to take notes but get familiar with it)
Read/do Ember CLI 101 - https://leanpub.com/ember-cli-101
Watch https://www.emberscreencasts.com/ (some of these are not free but it is worth paying in my opinion)
Building a professional level app will take time and practice, your first app/s are unlikely to be at that level without a lot of refactoring as your skills improve. One of the benefits of Ember (and other similar frameworks) is that you should have relatively small pieces of code so updating them later is quite pleasant.
It’s also worth trying to find someone to mentor you, there are quite a few moving parts in Ember and sometimes 5 minutes talking to someone who knows what they are doing will save you hours of frustration/confusion.
Good luck, it’s a great framework but as with all the best things, there is some effort involved to get the most out of it.
Thank you. I’ll try everything possible…
There is a step by step tutorial which drives you through on the basics, and you are building a complex application meanwhile: http://yoember.com
Thanks… That was helpful.