I don't understand what you mean exactly.
If someone goes to your 1st domain, do you want them to be automatically redirected to your 2nd domain?
If that is the case, then it depends...
The best option is to set it up with your Registrar. If you are registered with Network Solutions, then Web Forwarding costs $12 a year.
If your registrar doesn't offer forwarding, then you can set it up yourself. The exact steps depends on whether you are using Windows hosting or Linux hosting. If you are using Linux hosting, you can create an .htaccess file to redirect traffic.
Is redirecting visitors what you were wanting to do? If so, who did you buy your domain name from? Do you have Windows or Linux hosting?
Basic Linux Hosting on classic platform; Parallels Plesk Panel 10.3.1