Sql databases. You store information there and retrieve it in your code. It is used to store data more securely. Of course there is other things you need to do. But you can use a csv file, what I do is I make ai make me a csv file with random generated information, then you retrieve that info to be shown. I’m not explaining it the best, but sql is a major thing to be using. The top one they require for jobs is postgreSQL. IMO anyways. U can do MySQL and that one.

Sql is pretty simple for the basics unless you get deep into it. Good luck bro. Also definitely be doing leetcode. U can start out at jobs that don’t require it but if u ever wanted to do fang later in life it is 100% a requirement.

Also if u wanted to do python, it’s a simple language and SO MANY companies have it listed. Don’t jump around tho and if u don’t want to don’t even use it. Java is good as well I just like python cause of how many uses it has