Back in 2014 I started here. Was shooting (and casting, reloading) for the first time in 20 years.
I invested in a pair of Mosin's, an SKS, then caught the single shot Handi Rifle H&R/NEF bug.
Advice
A don't try to do it all at once. Take your time, enjoy the journey!
B Read, read, and read some more. IMO this place is the equivlent of a Masters Degree in casting, reloading.
But it is up to you. Pace yourself. If you find yourself wondering what to read next, read the stickies!
C Then one step at a time start putting that new knowledge to work. Carefully, cautiously, referring back here when necessary.
D Don't RUSH it.
E Each new caliber will teach you something, if you let it.