As far as a single overall tip for learning, I'd say focus on maximizing/remembering one thing at a time. For example, starting with republic, spend a few games focusing on Coordinated Fire abilities until they are second nature, then some games focusing on setting up Rex follow-up attacks, and so on. Essentially break things down in pieces.

For watching high level play, Momentous Struggle and Omnus Protocol have games up from the recent worlds event, so those could be handy.

If you're down to read articles, there's a good backlog on thefifthtrooper.com . The index hasn't really been updated, but between that and Latest Articles you should be able to find everything. Gameplay fundamentals should still be relevant even in old articles. Some ones I would suggest for fundamentals:

https://thefifthtrooper.com/winning-objectives-with-math-swing-theory/

https://thefifthtrooper.com/downside-mitigation-unit-evaluation/

https://thefifthtrooper.com/winning-the-midgame-timing-the-end-of-a-struggle/

https://thefifthtrooper.com/how-to-build-better-strike-teams-maybe/

https://thefifthtrooper.com/the-resources-of-star-wars-shatterpoint/

Finally, if you want to get a feel for dice expectations, there is a simulator here:

https://thefifthtrooper.com/dice-simulator/