If you don't have much knownleg about coding security then it may possible that your site may face time to time some issue. To improve the security , OWASP sugessions. The Open Web Application Security Project (OWASP) is a nonprofit foundation that works to improve the security of software.
You can check top 10 security risk of any application using below link
https://owasp.org/www-project-top-ten/
Discover SQL Injection vulnerabilities in web applications using OWASP ZAP, You can use below link
https://pentest-tools.com/website-vulnerability-scanning/sql-injection-scanner-online#