Hello student Generally C language is a part of syllabus in class 11-12 you can choose it with the help of your computer faculty if you're in school. If you're a college student you can learn C language from various website. You Can join online course and learn C language after completing the course you can also get certificate from the website.

Some of the best tutorials are as mentioned below -

1. LearnVern
2. Coursera
3. Udemy
4. Plural sight
5. Programiz

As you are a beginner and you're not familiar to C language you need to start from the beginning of C and then you can continue till C++ if you're interested.

Feel free to comment if you've any doubt

Good luck