You can indeed learn a lot online. You can almost certainly learn enough to do good work.
What school gives you is this:: a ready-made collection of colleagues (fellow students) and mentors (teachers) to help you understand why you're learning what you're learning. These other people will help shape your studies. A school also vouches for your learning by awarding you a diploma and maybe a degree.
So, if you want to, or must, study online, you'd be wise to find a community consisting of some peers and mentors. This community will probably be online. Don't neglect it. It will help you develop a critical perspective about what you learn.
You also should take at least some online classes that somehow certify that you completed the class work. That will help you find a job in the field you studied.
I'm sure you can succeed by studying only online. But you will be a pioneer doing that. It's not as well-trodden a path as going to school. So, you need to be prepared for the sorts of confusion and obstacles that pioneers encounter. One of the biggest obstacles will be convincing people you know your stuff. As long as you're up to that kind of challenge, go for it.
In today's rapidly changing world, it's likely you'll do both! Live classes, which are smaller and allow for participation and Q&A, offer an unparalleled learning opportunity through personal interaction. On the other hand, some subjects may require on-line instruction simply because there isn't a local teacher available to provide such a class. I realize not all students enjoy or do well within a standard school environment, but learning by interacting with others is pretty essential to success. And when that's not possible, then self-schooling through on-line courses is a good option.
As an educator, live classes are always better than online. Buse online as an option to study extra material above your course work, to set you apart. Gaining all types of knowledge is essential for you to be well-rounded. You can learn a great deal online, but not practicum work, and for sure, not people skills. I am very concerned about the number of people who have little people interaction due to the Internet and social media. Whether I was hiring for a position which required a college degree or not, I am always more interested in those who seek knowledge everywhere they can! So, unless you cannot afford higher education, please attend in person and learn, not only the subject, but things you can only learn through real one-on-one interaction with others in a classroom environment. You may get a job and do fine financially and emotionally through only online study, but don't limit yourself! Why be fine instead of great, as a person who is continually learning in structured and non-structured environments? Learning is a lifelong process, not just a step to a degree, diploma, certification or a job. Happy learning!
Let me make sure I understand your question. You said " Is it necessary to go to school when I could learn what I want online? Do I have to school before I make it in life?"
My understanding of your question is, "Why should I pay to go to school, when I can learn most everything I need to know to be successful in life by taking free online classes?"
Did i capture what you were trying to ask?
I agree with the three other responses, but let me add a little bit.
If you finish each class successfully, you will have the knowledge that regular learners have who take the classes. You may even successfully finish enough classes to get the equivalent knowledge of a college degree.
But would you finish successfully?
And if you finished successfully, how could you prove to someone, in one sentence, that you had that same knowledge that those who had the college degree had?
Individual online learning takes a lot of self discipline. The best online classes don't leave it up to the individual to discipline themselves. The classes are taught with a group of students taking the class at the same time, so they can interact with one another and give each other feedback and encouragement, and so the class progresses as a group to the end. There are deadlines that everyone has to meet at the same time.
Then there is this thing called accreditation. Schools strive to be accredited by accreditation institutions so that the rest of the world knows, in one sentence, that if you got the degree from MIT, or from Cambridge, that it means something. Teachers work hard to put their courses together in a way that effectively helps the learner to learn the material. The accreditation organization looks at all the courses in a degree program and if they agree they contain the right material and are taught effectively, then the degree program is accredited. Read more about it at https://en.wikipedia.org/wiki/Educational_accreditation.
So while it is theoretically possible, it is not a good idea. You have a very high risk of not successfully completing your goal without help from others who are committed to helping you succeed (like the teachers, the other students and the support people at the school). And you get what you pay for. If you don't pay the teachers and the schools and the accreditation organizations, you don't get the same recognizable high-quality degree as those who do. Like Ollie Jones said above, if you want to be a pioneer and are up the challenge of convincing others you have a good education, go for it. For me and my time, it is easier to earn the money and pay for the classes. Even if most or all of the classes are online.
Check out this school for a really good online program, that is a very reasonable cost. It has the advantage that while it is online, there are local groups of students and advisors who meet weekly face-to-face and support each other. The downside is, it is not available in all locations and there are some pretty strict rules that go along with it. BYU Idaho Pathway