Here's one simple example for you to begin with;
global start
extern printf ;from msvcrt
extern scanf ;from msvcrt
extern ExitProcess ;from kernel32
section .bss
name: resb 100
section .data
prompt: db 'Enter your name: ',0
frmt: db '%s',0
greet: db 'Hello, %s!',0ah,0
section .text
start:
sub rsp,40
mov rcx,prompt
call printf
mov rdx,name
mov rcx,frmt
call scanf
mov rdx,name
mov rcx,greet
call printf
xor ecx,ecx
call ExitProcess
;nasm -f win64 myprog.asm
;golink /console myprog.obj msvcrt.dll kernel32.dll
Try that out