1 - if you notice the pro photos, they shoot from the court. You are shooting from the stands.
See if you can get down on the court to take photos. position yourself to a corner or to the side behind a basket to get the action coming towards you. You'll get the faces in the shots then which helps with the shots.
2 - Many of your photos are not level. They need to be adjusted so that they are flat.
3 - your Shutter Speed is way too slow for fast action. 1/83 should be more like 1/800 or faster. You'll have to use Program Mode, or Shutter Priority, or Manual. Dependent upon what speed you need for how fast they are. The faster you get the more you have to review the faster motion parts of the players such as the hands / lower legs and ball.
4 - Your AutoFocus. Learn about the Different Auto Focus Modes and Areas. I don't know Canon but it looks like you are using an Auto mode ["Multi-point AF", but it also says "One-shot AF"] ? - you are letting the camera decide what to focus on. Get your self to a smaller area such as single focus point or some small group. So you can focus on the *exact* subject that you want to focus on.
Try those few things first.
1. Yes, I know they shoot from the courtside, so I'll do need to have a press pass or some kind of pass for me to shoot on the courtside on the next time that I'll go here, but I prefer to shoot in the Lower Box, which is a bit away from the court so I will have no direct contact to the players (since my lens still can shoot from this seat location, as long as it's not too far from my lens' range).
2. I didn't used tripod and I shoot handheld here all the time, so it's not easy. I know it will be harder when I use a better / faster telephoto lens since they're heavier than my current telephoto lens.
3. If I increased my shutter speed on that venue, my images will be dark or not bright and I have to edit it on a photo editing software for it to be brighter, but it will be noisier / has too much noise when zoomed in. I guess I need a better DSLR with higher ISO than 6400 and a brighter & faster telephoto lens to fix this issue... My shutter speed here is around 1/250 sec. and when I go higher than that, it goes darker when it's on my max ISO from my camera...
4. I use both AF and MF depending on the situation, since the AF of my current lens sometimes struggle, so I mostly use MF but sometimes it's still blurred on other shots... You can never predict their movements too since they're moving fast, especially when the players are really agile... I usually focus on the ones holding the ball, by the way.
Thank you for your feedback though and I hope you understand... :/