Hello I am a GIS analyst and I want to learn FME for the first time. I checked different parts of the website but still don't know completely how to start to learn here!

One way to start is to work through the FME Academy.

As a starting point, I would recommend looking at the FME Accelerator, I've heard lots of good things from those who tried it out.

In addition to the excellent advice by @david_r​ and @nielsgerrits​ I would like to add that a training course by your local reseller (and by Certified Trainers) is also a great way to get up to speed fast. See https://academy.safe.com/page/live-training for an overview.

thanks for your help

thanks @david_r​ 

thanks @Hans van der Maarel​