Hey welcome djati
The Nuke forum will be very helpful indeed.
Access to video tutorials will make things easier than the manual.
Besides here,Consider doing a course/term at fxphd and see if that model of education can help you transit faster.
Things that will take some getting used to
1.No desktop
2.No node kissing
3. 2D tracking will take a few extra steps and will feel clumsy
4. 3D system is not implicit like in action.You explicitly put 3d cards,merges etc down
5.Roto / paint is not quite there in Nuke
effortlessly navigating Flame is what i miss most (as opposed to nuke)
Play with Nuke for a month to get used to it's 3d system,python scripts etc It will get easier but you wont forget your flame in a hurry
b