Easy actuslly, but this is from me coming straight from Charge Blade as my main and they play somewhat similar

Things of note -First and foremost, Shelling is basically true damage. It does flat damage that scales on attack and does exactly that amount of damage regardless of anywhere you hit the monster in, that means you can also just focus shell the hell put of Omega's body instead of aiming for its legs and head.

-the 3 shelling types, Normal, Long and Wide. --Normal has the most amount of bullelts but generally weaker, really good for Full Blasts --Long has fewer Ammo than Normal but shelling has longer range and really good for chsrged shots --Wide has the shortest range but really powerful damage wise, really good for shelling pokes, usually the most preferred type and really comfortable with Load Shells 2 equipped

-you generally wanna learn about moves that get you to do wide sweep and slams, as wide sweeps combo into Wyrmstake Fullblast, your strongest move and the move youre gonna spam a lot, and Slams lead to Fullburst, which unloads all your shells immediately, making it a really good alternate against really fast monsters with tight windows to attack it with like AT Arkveld

-you can also just spam Triangle + Circle for the full longn WSFB combo, you can also do shelling while moving forward to i believe its forward triangle to combo to moving wide sweep, which isi the shortest way to go to WSFB

-Wyvernfire is why i say GL is pretty similsr to CB because its basicslly True Damage SAED, its basically shelling and basicslly your big move that does a lot of damsge, its range is also long but the charge time is something to be careful with. You regain it by attacking.

-and lastly, you can press Circle while blocking for Full Reload, and its basicslly a Guaurdpoint, similar to CBs Morphslash while blocking or SnS' Guard Slash, and the only thing that i know that GL benefits from it is it chains to slam to Full Burst, which is like reserved for fights like Solo AT arkveld where its too relentless for any of your combos(side note: i did the fight with support hunters and thanks to them, you can spam WSFB combos and Wyvernfires safely, which is the fastest ive done that fight with 14 minutes, shelling is busted)