What are the best resources to learn advanced Sketch?

Designer 🕶

Time and some articles on Medium.
Together with a goal you want to make seems like the best option.

Will ship code for latte's

I installed Sketch for the first time this morning and kinda got the hang of the basics and got my first mock up (for client) designed.
I used Gravit in the past, but Sketch is a lot faster and smoother. Similar functionality.