I recommend reading and working through the examples in The C Programming Language by Brian Kernighan and Dennis Ritchie. The book, while dated now, is an efficient introduction to programming and the C language for beginners.
The best way to learn c programming is training. Otherwise you will not be able to be a good programmer. Besides this you can learn c progamming language by reading c learning books or by using internet, but, it will take more time to become a good programmer on c . One thing more that, you should have knowledge also on mathematical terms and logic then you will be able to learn c very strongly.
1. Read a book that covers the basics.
2. Write a simple program.
3. Work out why the program doesn't work.
4. Make the program work.
5. Make a change to the program to make it do something different.
6. Goto step 3
Best way is by doing, as with all programming languages.
Actually doing it; to alleviate your fear: if you identify C/C++ as your requirement, you knew that #1 it is archaic, #2 it gets you low-level driver programming; #3 you can't get away from it. All these implies rather closed loop and you can get a working development environment rather easy.
One major exception is Visual C++ or its Microsoft Managed Runtime extension.
Follow the guide available on internet, you can also join technical classes and do practice yourself on daily bases. It might defiantly improve your language learning skills.
Plenty of decent mobile apps can teach you basics of C. A good book however is all you need. I cannot think of a n interactive online course for C.
By studying the practicing what you have learned!
I don't think reading is a good way to start
I think you need to start programming immediately