There is nothing bad in being a full-stack developer. However, it keeps happening that most people who are beginners just want to be in the front and back at the same time but it doesn't just work like that! Well first, let's talk about what being a full-stack developer means.
A full-stack developer is someone who builds both the frontend(user interface) of an app(which could be an iPhone app, android, or web) and also builds the backend of the app.
Now let's be specific about what the backend is, shall we? The backend simply means building the APIs and working with the database. So frontend and backend development are two different spectrums.
But here is the problem, people think that they are going to make more money by being a full-stack developer.
Hardly will you see a company hiring a junior full-stack developer! Well, you might say it's good to learn the backend right? Yea but not before knowing the front-end.
Big companies have front-end developers and back-end developers. Two different categories of developers doing different jobs. Only a few companies hire full-stack developers and they are majorly start-ups because they do have not many funds to hire developers separately for both disciplines and the start-ups also need the frontend and backend done in time.
Now if your goal is to become a freelancer and become your own boss, then being a full-stack developer is going to help you out a lot since you don't have to outsource the other part of the project. But you can't learn the backend without understanding the front-end.
Backend development requires a significant level of discipline because you are dealing with very important data. The code you write as a backend developer is so critical that you can destroy data and leave security breaches. So no company is going to hire a junior full-stack developer. Every developer who goes into the backend already started with front-end.
So here is my conclusion and recommendation: Learn frontend first to a considerate extent. It's also important that you focus on one thing first and don't transition anyhow. Follow me if you are yet to and share your thoughts and opinions in the comment. I'm gonna catch you later ✌.