First, install the assembler as illustrated in the video: x86_64 Linux Assembly #1 - Hello, World! at this link: https://www.youtube.com/watch?v=VQAKkuLL31g
Then you can use these commands to compile and run GAS files, once you have set the correct directory path in the terminal prompt:

nasm -f elf64 -o (filename).o (filename).asm

ld (filename).o -o (filename)

./(filename)