So the value stored at $7392 (ROM 9) is placed in A, and then that value is placed in $984A.
You got it!
Just one correction, though: it's not "h1", that's HL. See, CPUs use registers to store numbers, either to do calculations with or to use as an index. The Z80 in the Game Boy has a bunch of registers: A, B, C, D, E, F, H, and L. They are 8-bit registers, so they can hold just one byte. However, as you can see, they're paired up, so they can behave like 16-bit registers, and become AF BC DE and HL. The A register - both on this CPU and the 6502 in the NES - is called the Accumulator, and is the one that most arithmetic operations are performed on. The others are usually used for counters and addresses. Despite being paired with F, A can only work alone because F is used to store different flags, so essentially A is 8-bit - the main reason this is called an "8-bit console".
As for DE and HL, they're usually used for addresses. No surprise that in this example, DE is holding the address in the ROM to get the data from, and HL is holding the address in VRAM that needs to be written to, while A is used for the data itself. It's really quite straightforward, but if you ever get into hacking the NES, it's even easier: it only has three main registers, A, X and Y. A is the same as on the Z80, while X and Y are 8-bit registers used for addresses (ie you can't do any arithmetic on them). It sounds limited, but it makes up for it by having the first 256 bytes of memory (from $00 to $FF) be called "zero page" and has special instructions dedicated to it, so that's used instead of the registers. Some of those instructions allow 16-bit addresses on the zero page to be used, so in practice it's not really handicapped. And for a hacker, it can be easier keeping track of actual RAM rather than the registers, so I prefer the 6502.
So yeah, assembly is really not that hard, once you get the hang of it. Keep on experimenting and you'll be amazed at what you can achieve.