Wait times are long for many of the armor makers. The more expensive ones tend to have shorter waits lengths, but if you are on a strict budget then you will be waiting a bit unless someone is selling a kit. Unfortunately the armored costumes tend to cost more as many tools and parts are need to put them together. This is not said to discourage you, but to give you an idea of what you would be jumping into.
I built an Anovos kit and including the kit, tools, shoes, and extra things needed for approval in spent nearly $2000. I received my kit less than one year from purchase (I was on the wait-list for another maker but it was a year long wait so I decided to switch).
Many people who really want to get to trooping start with an Officer uniorm or Reserve pilot as they don't cost as much. That's what I did when i joined.
As for the age thing, you can spot some troops to get to know the group and ask questions about the costumes. It's a good way to learn what will work best for you until you are old enough to join.
Thank you so much! I also made another post that was a lot like this one but with some different questions. Another question, how much do you think I would have to pay to get the basic armor that can be approved when I do come to age. Also... what exactly is scouting? What do you believe to be the wait time would be for me personally. I know I'll need to wait but I'm eager to help people and learn.
Sorry for the typo. I meant spotting.

. It's where attend a troop out of costume and help the costumed characters to ensure they don't drop things, break their neck, etc.
If you don't have any tools available at all the cheapest TK would probably be around $1000-$1500. If you hang out on the FISD forum you may catch someone selling a kit for less than $500 but it's rare. So let's say you are going for absolute basic and you decide not to do the blaster for now your are looking at:
$500-$800 for basic armor kit (untrimmed and unfinished)
$70 - shoes (if you shop around you can find appropriate shoes for less and paint them)
$50-100 - black undersuit
$200 - misc tools (this will really depend on what needs to be done to adjust your kit to size)
$50 - snaps, rivers, Velcro, etc.
If you want a blaster and want one that is more screen actuate they run around $150-$200
Many people also put at least one fan in their helmet. Some don't but I'm promise you that everyone that doesn't gets super hot at troops. These suits are extremely warm. You can install them yourself if you know how to wire things or you can buy them and I believe that's another $70-$150.
If you know you are on a tight budget again I will suggest what has been suggested before that you save money and spend time with folks in the group. There isn't an exception to allow people under 18 to join. We have other Cadets that are close to your age actually. They too must wait.