That is a good place to start, but expensive. Not just the rifle, but have you priced .338 Lapua ammo lately? It was expensive before the craziness happened, I have no idea what it's like now. Even if you roll your own, it's gonna be expensive to shoot. And if you're learning the long range game, you're gonna need to put a good amount of rounds downrange to get there. Something to think about it.
How long of range do you want to go? The .338 LM is some serious long range potential, more than you can usually find around here (think 1000-2000+ yards). You might consider starting out with something cheaper to get into, cheaper to shoot like a .308 in a Remington 700 or similar. Just a thought.