You should be able to run your script from a shell command line, and it will print its HTML output to your shell terminal (STDOUT). Check the section of the CGI man page about "DEBUGGING".

If running the script at the command line causes an error instead of HTML output, the error message will tell you what's wrong and which line number(s) you have to fix in your script. If you still need our help at that point, you'll need to show us the error message, the relevant parts of your code, and maybe a small sample of data.