It's probably way too introductory for you, but the game Turing Complete gets you to make your own toy assembly language (twice for different architectures) in the later parts and this helped me immensely when learning assembly myself.

Its not windows or NASM but this site has some 64 bit linux examples using gnu assembler (the gnu userland default assembler). You could probably find some examples for windows with nasm if you look around.

::: spoiler example code from the site

# ----------------------------------------------------------------------------------------
# Writes "Hello, World" to the console using only system calls. Runs on 64-bit Linux only.
# To assemble and run:
#
#     gcc -c hello.s && ld hello.o && ./a.out
#
# or
#
#     gcc -nostdlib hello.s && ./a.out
# ----------------------------------------------------------------------------------------

        .global _start

        .text
_start:
        # write(1, message, 13)
        mov     $1, %rax                # system call 1 is write
        mov     $1, %rdi                # file handle 1 is stdout
        mov     $message, %rsi          # address of string to output
        mov     $13, %rdx               # number of bytes
        syscall                         # invoke operating system to do the write

        # exit(0)
        mov     $60, %rax               # system call 60 is exit
        xor     %rdi, %rdi              # we want return code 0
        syscall                         # invoke operating system to exit
message:
        .ascii  "Hello, world\n"

For the CLI commands: https://www.nasm.us/xdoc/2.16.03/html/nasmdoc2.html#section-2.1

Have you seen this?

I haven't written asm in years though, so I cant whip up a putc loop example.

https://labs.bilimedtech.com/nasm/windows-install/3.html