OK, Dsel I'll try to lead you through some of the terminology of a rifle and most will correspond over to pistols also.
1: Barrel center-bore: Take a circle and visually see a vertical line running down through the very center from top to bottom. Have you done a math problem and used a circle as an example and divided the circumference in half? Use the same scenario when looking at a gun barrel.
2: Straight edge: Using something that you know is perfectly straight(at least on one side and is long enough for needed usage). It can be a ruler, your eye sight by looking from one end to the other, or a piece of string that's brought taunt(like in concrete work with blue chalk string, to make a straight line on cement to guide the masons).
3: Railing: This is the flat bars with the slots cut out of them, like what's on the top of rifle to mount scopes or where iron sights are located. For Hi-Point carbine models, the front of rail has a lock down clamp that requires to be unlocked by raising up the lever. It's tight, so a flat screwdriver might help to unlock by putting blade into slot and giving a clockwise twist(by looking from left side of rifle).
4: Forearm: For our purpose this is what the opposite hand is holding to steady the long gun(rifle speak) while the strong hand is used to grip the stock or handhold while finger is used for trigger pull.
4-A: Removable Forearm: For Hi-Point carbines after unlocking the top rail clamp, you push the upper portion towards the barrel end to gain access to the barrel or in tearing down the carbine for disassembly of cleaning/repairs. Just look at either side view of carbine and you'll see a division split.
5: Front Sight: What the name implies. It's the sight that's closest to the end of barrel where bullet comes out. For the Hi-Point rifles this sight is held on by two(2) allen head type screws when looking on the sight's bottom.
6: Rear Sight: The sight that's closest to your eye when rifle is shouldered and centering the front sight post to shoot at your target.
7: Point Of Aim: (POA). This is the shooter looking at a target(be it an animal or paper) and using both front and rear sights (or optics if installed) and when pulling the trigger, the bullet finds the correct path to it's intended hit point. So if you are sighting one way and bullet hits at a different spot, there is some adjustments to do to correct the bullet's flight path.
7-A: Point Of Impact: (POI). This is where bullet has left the barrel and has already hit the intended target. ie: You're shooting at a target 100yds down range. You do your POA which is the intended bullseye of target, BUT you see that the bullet missed the target and stirred up a dirt cloud where bullet hit under target. This is your POI and with this knowledge you need to adjust your sight, be it front or rear depending on model of gun. It's almost like point of aim, but still different. POA is while bullet is still in chamber(before pulling trigger) and POI is where bullet has left the barrel and has hit where it decides(after pulling trigger). Many people use the terms interchangeably, but they are really different.
8: Shooting Bench/Picnic Table: While different they both serve a service when shooting. They hold all your equipment and give the shooter a place to sit, while being off the ground in a more comfortable way with something solid to shoot from, versus sprawling belly to the ground(prone position) and shooting.
9: Sand Bags: Sand bags are self explaining, but they really come in many looks and with filled media. Go to any local gun store and ask for sand bags for shooting and they might show you 3-5 different styles from pillow to v-block looks.
9-A: Shooting Vises/Clamps/Cradles: These are what you use when shooting from a picnic table or shooting bench. They are accessories that all rifle owners should have. They can be used to help clean, disassemble or assemble your weapon. Help with mounting a scope, or again help with shooting your gun to get the best possible accuracy from it by helping eliminate any breaths one does and helps steady the gun in an upright, vertical position that when pulling the trigger won't throw off the bullet. There is still shooter involvement in sighting, pulling the trigger and depending on shooting vise used, also shouldering somewhat to help with recoils and not let the rifle just go head over heals on itself and damage the finish. They give huge improvements over sighting in guns beyond the shoulder and holding method, so when you're out hunting and you miss your game, you know it's not the rifle fault as long as the game or target is within the proper shooting distances.
10: Barrel End/Crown: This is where the bullet comes out at the end of barrel. It's called a "crown" or in laymen's terms a barrel end. They come in many styles.
Target style: Flat outer face with a indented flat face. It's like taking a pie pan and imagining the outer edge is the barrel diameter and looking at the bottom of pie pan and seeing the indented portion with a hole in center for bullet exit, though not as drastic.
Concave Crown: Just like a concave mirror, but being done to a barrel's end. Like taking a drill bit and counter sinking a hole for screw head.
Convex Crown: A crown that's is not flat on its face, but has a gentle rounded bulge. A outwards bump if you want to call it.
Flat Cut Crown: Barrel end that's flat, with no other features.
11: Rifling: This is actually a two-fer if you will. The "Rifling" is actually the raised twisting ridges inside a barrel. There is also what's called a "Landing" which is the lower portions between the Rifling.
12: Rifle Twist: This is how fast or slow the "Rifling" is going down the barrel depending on gun/caliber. This is one that is best left to experts (which I am not) and is found easily on the internet.
I hope this has helped you in gaining some knowledge and don't be afraid to work on your own gun. It just takes time and effort and don't be afraid to ask questions or nowadays there's the Internet with all the U-tube videos . They didn't have anything like it when I grew up and worked/learned on and about guns. If I was anywhere near you, I'd lend a hand finding your problem and teaching you on how to find that problem from eliminating other possible problems.
If your really not sure of yourself in doing the sorting through the adjustments or eliminating of this, that and other, just call Hi-Point up and send rifle back to them with a note explaining what you think is wrong. They'll go through it and fix (no charge to you) and test the results and return the carbine back as good or better than new. Just remove any extra parts(scopes/reddots, risers, barrel shrouds, padded hunting sling or anything that isn't factory or is aftermarket).
Del