All of this is advice I've heard dozens of times, but there's a reason for it...
There's many avenues to get you started:
See if there's a way you can get involved with your school/classes (assuming its not a small community college or trade school) Most of the time they hire students as lab technicians. Its mostly sitting at a desk but you do get some exposure to the admin side. But if your really lucky you can get into a better technical position.
Talk with your professors. They are usually guys that have been in the biz at one point. If you're willing to show them drive and an opportunity to do some free work they might let you in on some of their project work. Or set you up with a grad student working on some thesis projects.
Fellow students/Friends in the business, sometimes its just asking someone you know if you can sit in on an install/upgrade, and help rack some gear.
Basically what that breaks down to is "networking" which I realize is an overused term. But reach out to people who have the experience you want and be willing to offer your time and knowledge (and worse case, brute strength) in return. Realize you have to go to them and say "Hey, I want to learn about xyz, if you have any opportunities let me know."
Being available is also important, sometimes its hard but a lot of upgrades/maintenance occurs after hours and on weekends. Some if it will be outside ones "comfort zone" but let them know you're willing and study up and help as best you can.
Also work for free/volunteer. There are plenty of not for profit organizations out there. But even then its hard to line up a decent gig, but even when its only you helping your friends move some gear, or doing updates on workstation. And learn what you can along the way.
Just be aware, no matter how prepared you try to be. Its always unnerving the first few times when you're flying solo or running the ship.
And after all of that, worse case, you learn something, have a few good references, and some honorable mentions on a resume.
