linux x86-64 NASM assembly [HELP!]

When I link against libc (using ld file.o -lc), a.out doesn't work. I can't execute it with ./a.out (no such file or directory), bash a.out (cannot execute binary file), and trying ldd a.out gives me «no such file or directory» too.
What am I doing wrong? inb4 “using assembly”

>>1
You fool, bash runs shell scripts not executables!

There's the assembler and the linker step. Find in which the error occurs, give us a better description of what went wrong and which messages you got for error feedback.