Free courses to start a career in IT
Most recently, I did the top skills that you can learn to get a coveted job in IT without any problems. If you haven't read it, I recommend reading it right now at the link.
I want to supplement that article a little and give examples of FREE courses, after passing which you will receive the necessary base to start a career in IT.
Note: This is not an advertisement, and I am not affiliated with any of the courses below.
Excel
Trumpexel is an excellent source for a 12-hour free Excel course where you can learn about all the rich features of Excel.

TrampExcel Modules
The course is very detailed and includes many modules that will suit both beginners and specialists with a background. I certainly recommend starting from the beginning even if you already know something, because there is a chance that you will miss details that will make it harder to understand and disassemble the module later.
Python
If all resources on the Internet are literature, then Learn Python in it is "War and Peace". A true classic and a great resource to get you started on your programming language journey.This is the best collection of tutorials with which a beginner is best to start.
Learn Python covers all programming language basics. After passing all the tasks and tests, you can get an excellent base that can be improved in the future (with the help of other resources on this list).

"Learn Python" Workspace
Upon completion of training, you can take a test and get a certificate if you have a strong desire. Learn Python together with LearnX provides such an opportunity.

LearnX Python Certification
Data Quest
Data Quest is one platform with many free courses. In fact, this is another alternative to the above resources, but the courses here are more focused on working with data.

Data Quest Courses
This is a great resource for those who don't just want to learn python, but already know what career path they will choose after learning this programming language - Data Analyst/Data Scientist/Data Engineer.

Data Analyst Course with Python
On the site you can find full-fledged free courses where an absolute beginner will be taught data professions. During the course, students create a portfolio for themselves. So at the end, it is already possible to look for a job.
SQL
W3school is a real treasure among all the tutorials on the internet. Here you can literally find information or a free course on any topic that interests you. Personally, I like web development and SQL courses the most. That's why I included this site in my collection.

W3school SQL Quiz
The course covers all the basic aspects of the query language, from simple queries and explaining the theory of what databases are in general to building more complex scripts, such as grouping data or joining tables on a specific column.
I highly recommend it, because for this course there is no need to download anything, everything can be studied exclusively from the browser.
Command Line
Learning the features and basic commands of the command line in a single course is not so easy, so I offer a course for beginners, which would be an excellent base for learning more complex, and most importantly, functional commands.

Udacity Command Line Course
The course from Udacity is quite short - the creators take no more than a week for it. Actually it's good. It's not worth spending more than a week on command line basics. This is enough to make more advanced courses easier for you.

Command Line Lessons
Command Line
To be honest, this is one of the most amazing free courses I have ever seen.

Introduction to Linux Course
Where else can I find a free 14-week course? Nowhere.
It is possible that this course will seem too long and lengthy for you. Believe me, it's not. This guy from below will not let you get bored.

Instructor Profiles
The course is very popular, and in this case it should inspire confidence. My recommendation!
Conclusion
I tried to briefly talk about each of the resources that I highly recommend for every newcomer to IT. If you decide to go through each of them, then, firstly, you are a very brave and determined person, and secondly, I wish you good luck and patience. It will take a lot of time and there will be many difficulties along the way. I want you to deal with them.
Good luck!