I've only been working on HTML and CSS for around 2 hours and it might be early to say but I'm already at 1/4th of the course so... what course should I follow after I finished HTML and CSS?
With the more courses... do you mean on this site?
no, i mentioned couple of sources where you can extend your html/css knowledge
What should I do?
Well, since you asked.
Don't rush it.
If it comes easy to you, then great!
One mistake you could make though, would be to want to get things done as quickly as possible to learn the next thing and then the next. I understand that it's exciting, but make sure to really grasp the concepts of both languages fully. By the end of the course, try to hack together a small project, see how that goes. If you can't come up with something on your own, you're not quite ready yet for step 2, in my humble opinion.
Now, you could either take my advice, or keep learning new things straight away. In which case, you should take a look at:
- Responsive Design
Edit: Hadn't seen @stetim94's answer. He's right, as per usual. Find out more about HTML / CSS before anything else.