Programming Fundamentals

Definitely check out CS50 on edx. It's widely considered to be one of the best introductory computer science courses.

There's also a four-course sequence of C programming courses on Coursera. I used these alongside CS50, to approach the concepts from a different perspective. Here they are in order:

Programming Fundamentals

Writing, Running and Fixing Code in C

Pointers, Arrays, and Recursion

Interacting with the System and Managing Memory

And if you're interested in hardware at all, the Introduction to IoT specialisation uses C programming with Arduino (the first course is an intro to IoT and the 2nd and 3rd courses deal with C/Arduino; the subsequent courses go into Python/Raspberry Pi so you can skip those).

Build Your Own Lisp may also be of interest to you. I haven't done this one yet but it was highly recommended to me.

That said, if you do decide to buy books at some point, I highly recommend the two books that are used in CS50: C Programming, Absolute Beginner's Guide by Greg Perry and Programming in C, 4th ed., by Stephan Kochan.

If you are interested in learning to program, it's usually more important to learn programming constructs and concepts first. There are also big differences when using functional vs imperative languages. And there are also different types of imperative languages.

My suggestion is to learn some of the fundamentals first vs deciding on which language. Take a look at the courses on Coursera - I believe some of the introductory classes may be free.

Some options to look at:

https://www.coursera.org/learn/programming-fundamentals

https://www.coursera.org/learn/algorithms-part1

https://www.coursera.org/learn/python

https://www.coursera.org/learn/intro-programming

Languages that some people start with include Python, C, Java

Functional languages include Haskell, Scala, Erlang