Welcome to the forum!!! There's a ton of knowledge to be had here. I run sterlok on my android and love it, I've only got the free version but multiple guns and all the info I need I can find there. I run a caldwell wind meter
it was $20-$25 and works just fine. It's good to have a reference for what you're calling the wind and I still struggle with it some days. I've shot my guns to about 1k and others out to 1600m, 338 lapua is fun in every department but buying ammo!!! Congrats on your pup too we have two of them and they're some smart hard hunting dogs for sure. Most of my game is ground hogs, coyotes, and deer it's blast stretching your legs on game after much much practice on steel.
I would hold off a little longer on the rifle upgrade and shoot the heck out of what you got for now. Once you're comfortable at longer ranges with your 300win then step up to the big boy 338, this is just the older guy coming out in me. I'm still trying to justify a 338 for myself and then figure out a place to shoot it at the ranges it's capable of. Your 300 will be sufficient for most shooting out to around 1200m a bit further is the wind is calm and you aren't shooting really big tough game.
I've spent a metric s**t ton of money on guns, ammo and optics over the yrs and figured out the hard way what does and doesn't work. Read every bit of info you can find, and read reviews I mean real reviews before you buy any gear or guns. Just because it's 'supposed to be' the coolest thing since sliced bread doesn't make it so. You seem to have a solid plan for spending your coin too, good binos are a must. I need to upgrade my spotting scope badly I've got an older leupold that's just not up to snuff now and I definitely got the short end of the stick on that deal, just one example of money that could've been better spent.
Anything past 1k is some serious business and will bring out every flaw in your shooting it's fun and frustrating all at the same time. My 308win wears a 3-12x scope with the horus h59 and will hang in there with the big boys at 1k if i read the wind right. Just keep your chin up and practice practice practice!!! You'll have your good days and bad but, once you can reliably hit targets at a given range move to game and have yourself a ball, being able to out shoot your brother and dad is always a plus too...lol
Good luck and Happy hunting