Printing only the file name after searching a pattern in the first line (using grep and head)

So I'm a beginner and i have a project due next week. I have to print only the filename of the files that contain #!/bin/bash on the first line. So far I tried this head -n 1 $filename | grep -l "pattern" but when I execute it instead of the name of the files I receive (standard input) Like I said, I'm a beginner and so far I'm familiar with simple commands. So I would like to know where I f****** up and if there is a way of acheiving what I want without using harder commands like awk.

for fis in  find -perm -a+x -name "*.sh" -type f
do
head -n 1 $fis | grep -l "#!/bin/bash"
done