Search bar customization …

I’m trying to change the “search” text in a search bar to an image. This should be a very simple procedure, however, I seem to be having a lot of trouble with it. I have tried using input type=”image” src=”https://ittakesballstoknit.com/laura-test/wp-content/uploads/2015/04/41-search-e1428088178932.png” (this is the url for the search icon image I’m using).
Unfortunately, when I do this I get a number of things happen, none of which is what I want.
I’m trying to get an image of a magnifying glass (search icon) to appear, and when the user clicks on it, the search input box opens up for them to enter their search parameters.
Any help you could provide would be appreciated.
This is the site url … https://ittakesballstoknit.com/laura-test/

Hugzzz ??