I would simply say that it's honestly not as difficult and daunting as it first appears. I'm an older user (63) and I think it's completely logically set out; there's a signal path set out right in front of your eyes in the buttons on the unit, to the right of the master volume - stomps, then amp/cab, and finally mods/delays etc. after the amp/cab.
Personally I use Rig Manager (RM) a lot to set up Performances and import rigs. As others have said, there are lots of videos online to help out.
I would say:
1. Remember there's a difference between Browser and Performance mode - the former is to store profiles or audition them, and the latter is there to set up banks of Performance patches for playing live, with your chosen selection of effects etc.
2. By all means buy or collect profile packs, but don't be tempted to import them all into the unit itself. You can import and audition them easily within RM. Once imported, back up RM regularly. It takes seconds.
3. Within Performance mode, get to understand morphing. It's a great feature.
4. Again within Performance mode, there are 125 fixed slots available on the unit itself (unlimited within RM, where you can set up folders). Most of these will be labelled 'New Performance' - you change the name once you've set it up. There are a set of example ones installed, called things like 'Example: Song A'. I wouldn't touch those.
5, Each Performance will hold 5 rigs (1-5 on the bottom row of your Stage), each with its own selection of stomps/effects etc (buttons above). You can copy rigs to these slots. The Up/Down arrows navigate between Perfs.
[Many people set up one Perf. per song. Personally, I set up one main one based on different gain stages of one specific amp, from clean to lead, with appropriate rig volume changes; then have a similar separate one for E flat, one for drop D, one for a very specific song (requiring completely different rigs), one with an acoustic patch on it, one completely double-tracked.]
6. Assigning effects to the buttons on the top row of each rig is dead easy. Myself, I select and set up the effect using RM, as it's visually easier, but of course you can do it on the unit itself, it just takes longer (for me). Then once it's there, press the coloured soft effect button on the Stage that you've selected for the effect, and the metal stomp button simultaneously, and it's assigned.
7. Always remember to Save when you've made a change, and you're happy with it.
8. Once you're familiar with those basics, look at morphing, and more obscure things like Clean Sens/Distortion Sens, Definition, Clarity etc, how to set up expression pedals, and so on. Also how to assign outputs (e.g. Main Output - Mono or stereo? and Main Out volume; Monitor outputs)
P.S. Despite what it says on my user status, I'm not a Beginner..!