What does it take?

I'm a front-end developer. It took me about a year with on the job training and self-learning and building websites myself to get up to speed for junior positions. Since then (10 years ago!) I have been learning new things all the time, brushing up and so forth - HTML5 and CSS3 was really only more readily available to use after 2011 - because most people still were using older browsers and it was harder to account for cross-browser compatibility, and even on a continuing basis you have to keep learning new better technologies.

Having a foundation in object oriented programming is helpful to understanding javascript so your knowledge there is useful. I would continue and finish the front end track on Treehouse, and then continue some more advanced CSS.

You do need a portfolio - everyone will ask for one or if not, will wonder why you didn't provide one. It shouldn't take too long to build one. A couple tips: Do not use a CMS like WordPress or a template from somewhere online to build your portfolio - code from scratch about 5 test sites - you can use subdomains on your own server (get a domain/host) and make sample websites for various types of businesses. Make sure your code is all W3C standards - compliant and clean.

Then yes you can start applying to jobs!

After learning Javascript (Object oriented, design patterns) then you should learn some MVC framework, Angular.js or Ember.js are recommender. Then practice a lot and at last look for a work.

I'm an all-around web developer right now (we're a really small company, so while my title is "Front-End Developer", a lot of what I do is considered back-end programming); I absolutely benefitted from having a firm grasp of object-oriented languages. You don't need to know every language--it would be really confused if you did--but you should have a good idea of how they work. If you're specifically interested in front-end and you're looking to build a portfolio quickly, jQuery is an easy, design-oriented version of Javascript that can help you get started. You're also going to want to get cozy with Javascript (technically, if you learn this first, jQuery is a cakewalk because you'll have a good understanding of the principles and much stricter coding habits).

Angular.js is a great, in-demand language right now, but for starting out, I think Node.js is a little easier (just opinion, though, look at them both and decide for yourself!).

Finally, when you're building your portfolio, make sure you work with different free platforms so you can get a feel for their architecture. I work mostly with ecommerce sites when I'm freelancing, but those are jobs that I've gotten because I have experience with X or Y platform or framework (such as Zend framework/Magento, Bigcommerce, which is a SaS, etc.). Many of the most common platforms are open-source or offer free developer trials, so it doesn't hurt to familiarize yourself with them if you see yourself working in that direction in the future.