First Timers Support with CPIMS+ Rollout

Any advice for first-timers?

You should try to quickly work out the difference between what your requirements are (what your finished system should look like) and what comes out of the box with Primero. Then you will know if you can do the customisation using the UI or JSON or Ruby.
It is much less error prone to modify and add existing forms than to create a whole bunch of new ones.