Welding is not over complicated, with in a few months of practice you could have the basics down.
Becoming good at a process or more importantly, all the processes, will take a lot more time because you need arc time to get better and that means a lot of welding.
I wouldn't say it's difficult to get a welding job, but the best paying jobs are reserved for the most experienced and certified guys, which means starting out you probably won't be making a ton of money. If you are uncertified you will pretty much never make enough money to retire early, if you have alot of rare certifications such as ones for rare alloys and exotic metals/ high pressure welds you can get a 6 figure job. I went to college for welding in a 2-year program and I thought it was very easy, if you use your shop time wisely you can stay on top of all the projects and even get ahead and the book work was pretty basic, if you can read and write you should beable to pass with flying colors.
Everyone learns welding a little differently, some people may excel at one process and be terrible at another so you really have to find your niche and just practice hard to work on your weak points, as a welder you will get paid for what you can do, so the more versatile you are the better.