What is the best Workflow? where to start

The order has been usually acknowleged, over the years, to be generally the same as the treatment order in an audio mixer (the hardware variety). You start with getting the levels correct, then any compression you want is applied (this is why the insert point on the mixer channel is where it is), followed by EQ. There is some debate as to where NR should be applied, but after the EQ generally works fine, as you can hear the subjective result more accurately at this point than if you'd done it earlier, but that isn't always the case...* If you do it earlier, you potentially end up with 'shaped' NR. So, you tune the dynamics early, not late as a rule. If you do it in any other order, you stand the risk of a previous effect being modulated by a later one, and that's the fundamental principle - you want to avoid that happening. Once you've got that in your head, everything else is relatively simple!

*NR is the interesting one. There's a lot to be said for doing this first, because this can make it clearer as to what else you need to do. It also, in theory at least, reduces the amount of background that would be modulated by any form of compression, so it's probably worth doing this earlier.