What is the best coffee brewing method to learn at home? What equipment shall i prepare? I have been watching youtube videos and all sort of guides and books. I have been watching pour-over method and wonder, does the equipment i have to buy to practice at home should be expensive? Im still in my 2nd year of college. What should i do to learn skills necessary to qualify to be a barista?
I am unsure if you are comjng from the perspective of someone who wants to become a barista or someone who is interested in making quality coffee at home. 

In my opinion learning how to brew quality espresso, and the different factors that effect a quality espresso and espresso drinks is most challenging and also requires the most knowledge (how to prepare the grinds, the whole milk steaming/foaming process etc.) it also requires expensive equipment unfortunately. I think these skills would be good if you are looking for a barista job though. 

For brewing at home i think you should master the french press which is a very inexpensive method to brew coffee (french press being like $20 for a good one) but is also my favorite coffee brewing method. It is also very simple to brew, you just have to make sure you get the correct ratio (using a scale is best) of water to coffee and grind the beans well (a burr grinder is best but can be kinda expensive. This would be a cost of any brewing method should you decide to grind your own beans).