Many people get stuck while learning how to code cause they don't find good resources. And I was also in the same position few years ago. So, here are few free resources to learn how to code and some of them even offer free certificate while some charges(for certificate only).
Official google developers teach you CSS with great examples. They even do CSS podcasts.
Here you find great tutorials from Harvard professors for free.
Another top university offering free courses ranging from Mathematics for CS to Machine Learning.
A great learning resource that is completely free. Get courses from learning responsive web design to data visualization and machine learning. They even have YouTube channel with over 4M subscribers.
Another well known top university for Computer Science located near Silicon Valley. Definitely worth a visit.
Khan Academy is an American non-profit educational organization that provides free courses for learners who wants to learn Computer programming, Science, Maths and many more.
Yeah, they do provide courses from Harvard, MIT, Stanford but they also provide courses from other great universities. Like this one Introduction to linux.
They collaborate with 200+ leading universities and companies and provide great contents and programs. You can audit most courses for free but you have to pay for certificate.
Hope you liked these resources. If you know other resources then let me know about them in comment. And what will you do with certificate - nothing. So I recommend getting valuable knowledge.