I'm not sure if you're referring to Magento 1 or Magento 2. You've posted in the Magento 1 forum but tagged as Magento 2.
Both platforms by default show the search form so I don't know if you're using a purchased theme? You could look at the themes shipped with Magento to get insight into how it could be done.
----
If you've found one of my answers useful, please give "Kudos" or "Accept as Solution" as appropriate. Thanks!