Any tips for running PHP safely?

Question

I took a small hacking course and relised that php can be exploited to certain degrees to gain access

Answer 1

Everything is hackable my friend...but with certain steps it can be reduced. Its same with every technology. Some are secure by nature(Java for example) some are not. PHP is not that secure compare to other languages. But you can make a secure backend by following steps:
1. Using a PHP framework. Laravel is the best option.
2. Use OOP concepts.
3. Validate user inputs by passing them through functions like htmlspecialchars(). It will make your application safe from cross site scripting