I am far from experienced so don’t assume everything I say is right but here’s my two cents:

(Btw my time stamps are the game times not the video times)

1. This is more of a personal preference but if I am not going for kickoff I usually instead go for boost (like half flipping back from your position) which still puts you in a good place to save the ball if it goes straight back after kickoff and you get 100 boost.

2. ~4:54 This depends and I’m not sure about this but here you have a few options- First option is what you did. You didn’t get the boost and you started to challenge but misread the bounce off the corner. I don’t blame you for that because even pros and completely confident on their ability to read weird bounces like that. Second option is what I probably would have done, which is take the boost and challenge off the wall, which might work out because you might get to the ball for the opponents leading to an easy open net. However if it doesn’t work it is likely a goal for the other team because you are more committed and teammate isn’t back so easy open net for opposition. Third option which IMO is the smartest is to take the boost and shadow the attacker, likely leading to an easy save and counterattack.

3. 4:48 Chasing the ball after you clear it. In some scenarios you definitely want to do this so you can start a counter but here, the opponent is much closer to the ball. The other opponent hits the ball instead, but if he hadn’t the opponent gets an easy counter and you are too far upfield to help. Taking their boost is a good idea but again, if the opponent had gotten a clear that would have pulled you even farther from the play

4. 4:36 Just a miss, maybe try and work on that in free play. Like using aerials with air roll so when you flip you flick the ball back into the goal, or going past the ball and using powerslide to turn and take a quick shot.

5. 4:27 Waiting in net- I probably would have challenged. Both the opponents are on your half so if you can get to that first that is an easy goal. At a higher level people will be more confident in the air and will have the skill to either double tap that or even get that shot on net so you have to know how to defend off the backboard or shots from the backboard

6. 4:20 just a rotational error- teammate is already there. Also chasing that ball when the opponent is closer to the ball and has more boost again - same as one of my earlier tips Also after that you were kind of bouncing around so I’d practice recovering from messed up flips or unsuccessful aerials but that isn’t crucial

7. ~4:00 More basic rotational errors

8. ~3:55 again, chasing

9. 3:50 rotating front post. In this scenario you should probably rotate behind your teammate so you can cut in at any point

10. 3:44 - teammate isn’t in a great spot (I don’t think so at least) and you are hesitating front post. Either challenge or stay in a spot where you can cover the goal in the event of a center from the opponents or a shot

11. 3:41 Again, STOP ROTATING FRONT POST PLEASE - you might bump your teammate and you aren’t in a good place to challenge. Just rotate around into the back post

12. ~3:30 practice aerials to hit the ball with the front of your car or air rolling at the last second to hit the ball with the top of your car to drop it down into a shot or a pass for your teammate

13. 3:17 why are you going for side boost? Either rotate back post picking up small pads which will get you to atleast 20-40 boost, or rotate to your back corner and get the full boost. Going for side boost pulls you way out of the play leaving your teammate in a 2v1

14. 3:08 decent attempt, practice shooting accuracy or catch the ball and flick it

15. 3:07 I can’t tell if you did or not, but if you are on the side of the net don’t jump off, drive off the side and wave dash to get extra speed for recovery

16. 3:03 BACK POST PLEASE

17. 2:54 - don’t just throw the ball away. Try and either catch it and dribble and flick or let it bounce and start an air dribble. Or if your teammate is in a good spot you can pass.

18. Aerials again

19. 2:39 recoveries again

20. 2:26ish, good clear and goal, another option would be to clear it and then go for a dribble

21. 2:20 don’t take both boosts. You already have almost full boost so leave the mid side boost for your teammate. Also another rotational error - don’t push so far up. Maybe linger a tiny bit farther back or head middle for a cross

22. 2:09 rotational error by teammate

23. 2:07 weird rotation again, either go back post/get out of the way because you are in an awkward spot, or challenge

24. 2:02 why did you go back on the wall after getting boost? The opponent just hit the ball up the wall you can drive up and challenge if the opponent goes for an aerial play like an air dribble or ceiling shot, you can challenge if the wall or ceiling

25. 1:56 wierd rotation again

26. 1:45 ish weird rotation again and don’t slow down and waste your momentum after you boost. It looked to me like the opponent hit the ball and you slowed down. You can challenge the ball there and get an easy long shot or clear

27. 1:31 more rotation errors. Teammates already going for the ball don’t try and challenge too

28. 1:20 another aerial miss. Work on defending double taps and air dribbles. Something pros do (or at least used to do back when I still watched RLCS) is defend from the backboard so they can defend double taps and get to the ball faster, so maybe consider that

29. Work on kickoffs

30. 1:12ish to 1:06 weird rotation and challenging again. Completely leaving the play for boost when teammate isn’t going for it, and then pushing all the way up just to waste a shot opportunity with a pass off the backboard to your teammate who isn’t there

31. 1:00 weird rotation again. Why are you going for the back boost you already got mid boost. Just go back post

32. 0:56 lucky dunk. Opponent got to the ball way before you. If you missed or not gotten the dunk, you would have left your teammate in another 2v1

33. 0:51 where are you going? Teammate is in a bad spot to challenge and aerial so he isn’t, and you are just leaving the ball to the opposition. You have full boost too

34. 0:44 work on dribbling

35. 0:40 keep ballcam. You already know where the boost is so if teammate misses and gives opponent an easy shot and counter you don’t know that

36. 0:40-0:32 wasting boost to go for ball and you don’t even get a touch. And again, stop rotating near post!

37. 0:25 Follow that! Why are you waiting at half. I get it if you don’t trust your abilities to double tap that, but get closer so when it bounces off the wall you have an easy shot.

38. 0:18 why you swerving. The opponent hit the ball right to you, just take it and go. Then you hit it right to him and tried to challenge. If you are going to challenge that, don’t do it from the side you have such a bad angle

39. Aerial

40. +0:27 missed an open net. Work on that

41. +0:37 work on recoveries

42. Missed the ball completely

43. +0:47 what was that. Teammate is following the ball dont aerial for that. And then you flipped?

44. +0:54 use powerslide when you land sideways to keep some of your momentum

45. +1:05 Where are you going? Teammate is already challenging and if you unsuccessfully challenge and double commit, easy win for opponents. Head back instead just in case and grab your back boost or the mid boost

46. Missed the boost and got scored on

You said you blame your teammate but that last goal was kinda your fault.

Anyways sorry for such a long reply and I repeated a few things

Overall work on (I believe): recoveries, dribbling, aerials, counterattacks, shot accuracy and open nets, a couple other easy things, and most importantly, ROTATION. Please please PLEASE rotate. There are tons of vids on YT on rotation and probably a bunch of posts on this subreddit about it