Any somewhat decent RP-1 tutorials out there?

[Actually_New_KSP_Player]

I'm new to RP-1 and after reading few tutorials on the main GitHub page I'm still kinda confused as to what and when do i do with all those new options like tooling, constructing rockets, researching new stuff while it takes a whole one year for the first node(???). Things like FAR window, TestFlight's reliability and data units, the point of rated burn time and so called engine overburning, how do even set the tank priority(?), what's the point of all those empty tech tree nodes, crew training and "Press the KRASH button to enter a simulation." are left unexplained. Though i'm not sure if the "flight simulation" and the KRASH button is a metaphor/joke or a real thing. Anything i should read/watch about those topics? I've seen some NathanKell's videos, but he didn't explained much of the stuff there plus his videos are fairly old, even the tech tree is different now.

I'm using 1.6.1 version btw.

Edited July 21, 2019 by Actually_New_KSP_Player