There are many ways to get into it, but for the most part it's all about direct connections.
• Network with professional VJs, lasers, sound, and lighting services. You can work freelance to produce content and/or actually play at events. You can probably get paid to make content, but you'll only be able to help out at shows (for free) until you learn the ropes and prove you're reliable. This is the most common path.
• Contact artists directly. You'd probably just have to make free stuff until you develop a good enough reputation to get paid. This is showbiz, so there's a pretty high bar.
• Try to work at a company that does visuals. It's extremely competitive and there are not that many seats available. The first two options are your best way into this later on.
• Do it yourself. Buy a projector, contact your local clubs, raves, event promoters and offer to do visuals. Plan for very long nights. Consider doing guerilla visuals around your town.
• Keep releasing content. Pitch them to VJ loop services like vjloops.com or Resolume. Learn marketing, etc. There's very little money in this, but if you get good, you'll at least make a name for yourself, which can help with the other options.