Fix my website's search results

I am looking for help to resolve an issue with my e-commerce website. I have access to the source code, and the website is written in PHP. The problem I am having is that search results from the website are not accurate. I need help troubleshooting this issue and developing a solution so that my search results are accurate and helpful for my customers. Please include in your response any relevant experience with troubleshooting search results for websites.