You're aiming to be a self taught dev, right?
More important than any language, the first thing you need to learn is not to be lazy and to do your research well before asking for help. GOOGLE IS FREE AND ALWAYS AVAILABLE!
To be 'self taught dev' you need to learn how to search and how to find the right answers. You'll have 100's of questions while learning, and even the most helpful person won't be there for you all the time.
Working as a devoloper you'll find yourself googling stuff all the time. You'll find yourself reading documentation every now and then. If the documentation is 100's of unorganized pages, will you read the whole thing? Of course not! I'd you don't know how to get the answer out of this mess you won't go far.
Learn how to search properly, learn the tricks people use for better search results. Along the way, you'll find yourself gathering a list of websites (mentally) that will be your main source of technical knowledge and you'll use the alot later on..
I hope that you consider this as your first lesson!
let's put this into action;
Googling your exact question 'What common programming languages should I learn? Also, what else do I need to learn?' the first page is full of reputable websites all answering your question. Of course answers may vary, but the detailed ones will give you great insights and you'll know the way to follow!
Since you're interested in web dev, I'll pick you one of the results;
https://www.freecodecamp.org/news/what-programming-language-should-i-learn-first-19a33b0a467d/
Why exactly I'm choosing this particular result?
First, it answers your question well enough.
The second and the main reason is that freecodecamp offers great free courses that follows a good roadmap and will make you do many projects yourself to practice what you're learning. They also have a great YouTube channel with extensive video courses and great walkthroughs.
Those are the main topics you need to know about to become a good web dev.
Enough talking! If you're serious about this, TAKE ACTION and start now!