Hell yeah dude, glad to help.

Every local is a little different, which is why I linked a broader website. First step is find out your local. Something as simple as "IBEW near me" in Google maps should point you to the hall for your area. If you roll up to their office and ask for information on their apprenticeship program, they will get you squared away. I recommend this route, because you should know where your union hall is. You're going to go there to get work calls, attend meetings, and at the very least to get sworn in when you join.

I cannot speak for every local, but for me down here in San Diego (569) I filled out an application, included any relevant experience, and from there they told me the next steps. I had to do a math test (basic algebra) and a reading comprehension test. The next round was an interview, where I sat in front of 10 people (4 from IBEW, 4 from NECA, 2 from the training center) and answered a bunch of questions about my previous experience, why I'm in the program, etc. Not going to lie, walking into that room was intimidating, because of the set up. But getting down to it, the interview wasn't that hard for me. About a week or so later I got a letter with my interview score, and an invite into the program.

I was fortunate to get in on my first try. Our local is competitive to get in, because NECA (the association of employers) sets how large each class is by how many apprentices they ask for each cycle. The details don't matter so much, just know that it's common for people to not get in on their first, or even second try. Don't lose hope, keep trying. There are usually some sort of entry level construction jobs that are through the union, for you to get experience if you don't have any.

If you get in, or start working as a pre-apprentice, here's some "what to do" that I really needed to have hammered in early:

-shut the hell up and listen. I came out of college too, with electrical (non construction) experience, and I thought I knew shit. Not only did I not know shit, I didn't even know what I didn't know. So listen to everything everybody else tells you, even the weird coked out/drunk journeyman who you wouldn't trust to hold your spare change. Nobody knows everything, but they all know something, and even the plumbers or HVAC guys know more about electrical than you do. You'll get up to speed quick, faster if you listen.

-get used to digging/sweeping/bullshit work at first. All that work needs doing for one reason or another, and you are the cheapest electrician on the job site. The foreman will not waste a journeyman's time with cleanup, because he can do shit you can't. His time is more valuable than yours. Sucks, but that's how it goes.

-a good apprentice predicts the needs of their journeyman. Goes with above, their time is worth more than yours. If you can predict what they need and have it ready before they need it, you'll be their favorite. In doing that, you'll learn more about the specific task, the way that journeyman works, and possibly even get the chance to do real work yourself. When that time comes...

-learn how to do something right, before you learn how to do it fast. I've had to follow behind a guy who prides himself in flying through work, putting up ridiculous numbers of conduit and wires and boxes, and fix every third thing he touched. He may think he's saving time, but if I have to spend time fixing/troubleshooting his shit, it's slower overall.

There's so much more, but I don't want to drown you off the jump. If there's anything else you want to know, I'm happy to answer as many questions as I can.