This may not be exactly what you are looking for but if you have specific topics you wish to learn more about then the Security [1] portion of StackExchange contains some decent questions and answers. ServerFault [2] also contains some server best practices. Stack Overflow [3] would have some of the coding best practices. Lurk on there for a while before asking questions as people expect a certain style of question formatting and some degree of research from someone in a related professional field prior to asking questions.
[1] - https://security.stackexchange.com/
[2] - https://serverfault.com/
OWASP Cheat Sheet Series [1] is a great place to start (for websites or HTTP services generally). Also see their Web Security Testing Guide [2] for a comprehensive list of security issues to watch out for:
[1] https://cheatsheetseries.owasp.org/index.html
[2] https://owasp.org/www-project-web-security-testing-guide/lat...