I would suggest that first you should familiarize yourself with the basic principles of the process by reading either text book or a few recent review articles - there is no shortage of the material -
There are numerous free online tools to design primers, including the NIH site. The understanding you will acquire through reading, will help you select appropriate parameters rather than simply relying on the default settings of various programs.
On the hand, if learning well does not interest you, search through the literature and copy someone else's published primer sequence and hope that they did a thorough job in designing their primers.
Obtain the mRNA sequence for you gene of interest from UCSC. If there are many isoforms of the gene try to select exons that are relevant to the transcript you are wishing to detect. Use primer 3 to generate primer sequences. Verify that primers span at least one larger intron and that they are specific to your gene of interest using