You’ve been building up quite a robust set of tools. You have PHP scripts to receive requests from your HTML forms. You have MySQL to store information from your users. You have regular expressions to massage information into just the formats you need, and some basic flow controls in PHP like
for to let you build scripts that make decisions based on what information your users give you.
But, at the end of the day, your goal in learning PHP and MySQL was probably to make dynamic and interesting web applications. Unfortunately, you’ve not done much of that yet. You do have a few interesting forms, but even those are simple: take in some information; print it back out; accept a SQL query (and do that quite imperfectly). So, where are the web applications? Heck, where are the pages that are built dynamically using your user’s information?
Thankfully, you have everything you need to start building these kinds of web pages. You can get information from your users, store it in a database, and even do some basic data manipulation. All you need to do now is put it all together and create the basic web pages that most users expect: a place to enter their information, a place to look at their information, and in most cases, a place to look at all the related user’s information.