First of all, welcome.
Second, congrats for giving a damn....and I would say you are probably better-dressed than 97% of young men your age.
With all of that said, the fit of the suit could be a bit better by the standards Style Forum is known for. The average person (and many above-average people) would take a look and say, "wow...he looks sharp" so you should feel completely confidant wearing that entire rig out for an event. Considering you bought it used, you are fortunate it fits as well as it does. Here are a few things I observe: 1) I think the sleeves are a little bit short. 2) The hem on the pants might benefit from being a little bit longer, but it is such a slight difference that if they slipped down a quarter inch from your waist it could make all the difference. 3) the jacket is a hair short for classic business purposes, but it looks within range of a more "style" cut that seems to be popular with you young'uns these days. 4) There is too much gap between the jacket collar and your shirt collar-this being one of the hardest parts to fit. I think the shirt collar is just about right for you, but with the wide opening it seems too small. The shoes look solid and I like the shirt. I don't have any religious objections to the tie, but I think you can do better.
I hope this is helpful. When you have more resources and go out in the world find a professional suit salesman and I think you'll see and feel the difference when you get a suit that fits just right. Good luck!
Thank you MrDaniels for the constructive feedback, I greatly appreciate it! I find it extremely helpful. And I totally agree with the sleeves being short. They are about .5-.75" shorter than my professional tailored suit. Since it's a functional cuff sleeve, I'm a little uneasy about taking it in. But for the price I got for it, I can live with it!
The trousers do seem a little short. I just started wearing braces because I like how the pants drape, and they hike up my pants a little too much resulting in it being too short. I have thought about letting out some fabric the next time I visit home.
And for the gap between the collars, this really irritates me! I even have the problem with my other suit. Is there anything a tailor could do to help fix that problem?
And hey! I might BE that professional suit salesman! Tom James Company heavily recruits my school and I have talked to them about employment after graduation. However, I've heard a lot of things that I wish my ears hadn't about being a sales rep for them so I've got some thinking to do!