Repairs with Ruger are handled by Ruger 99.99% of the time free of charge and shipping cost is on them. Just call them about any problems you have and they can get you a shipping label on the way. However, some problems are simpler than others and can be answered here.
As for your SR9, it's a good gun but some have seen instances where Peening (barrel block deforms a small amount against the slide and can cause issues) occurs or some will have Trigger Reset issues (the gun fails to reset the trigger after some or all subsequent shots).
The Peening issue is, from what I can tell, random. You won't know you have problems with it until after a couple/few hundred rounds and sometimes you won't see or catch it until much later, approaching 1000 rounds. The Barrel Block, as I call it, is the beefy part of the barrel/chamber that's visible in the middle of the slide. When the gun cycles we think the main issue is timing and the two pieces of metal hit every time eventually causing damage/deformity to the weaker chamber (it's not stainless steel like the slide, both are cast metals in this case). There are many threads on this with pictures, but if you ever see a ridge forming on the leading edge of the chamber/barrel block, feel free to start a new thread and please post pictures, it makes it much easier for us to determine what's up. Worst case scenario your gun can lock up if you shoot it too much with the peening issue. Most don't get that far, if you catch it to any degree Ruger will almost always replace the barrel, but quite a few people with this issue won't get it resolved in one trip, but Ruger will do what they can to fix it. This is the main problem with this issue, it's random, and there's no real 100% known reason to what's causing it.
The Trigger Reset issues, aren't anywhere as frequent but it's one of those things that Ruger will have to look at, and sometimes it's not resolved on the first time. There are a few threads on this as well, but this issue is fairly rare given the guns decent popularity/sales.
Despite those 2 issues I described, don't get worried about it, relax and enjoy your SR9. Many of us SR9 owners have put many trouble free rounds down range. I myself have over 1250 flawless rounds but I am nowhere near what some others have through theirs. If you find yourself brave enough to dive into the internal operations of the SR9,
check out this link for my How-To thread. Inside you can see detailed instructions on how to do Field Strips, Detail Strips, Magazine Disassembly and also some tips on Polishing contact points to smooth up the trigger, all with hi-resolution pictures.
Welcome to the forum! The laser you bought is a pretty good one from what I hear, I think you'll like it. Setup is basically installing the batteries, slipping it on the accessory rail, then hitting the range and sighting it in. There should be 2 screws perpendicular to eachother to adjust it's elevation and left/right alignment. I don't have one so I can't say whether or not you'll need your own tools but it could be a small Allen screw or small machine (slot) screw.
But like everyone else has said, 50 yards is a bit much for a pistol, let alone a new gun owner, stick with 7-10 yards to practice Self Defense shooting, and then move it back to 15-20 yards. This pistol is more than accurate to protect yourself with, but it's no rifle
. Stay safe and enjoy your SR9!
Josh