Disclaimer: I am by no means a professional nor do i consider myself to be good at the game. This is just what I saw and anything that I note can definitely be misinformation.
I'm just going to analyze the first game vs. Oreo for you, but i'm going to be purposefully vague because I think you will learn better if you figure out the entire mistake yourself.
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0:32 - The walljump to sideB was the best option in that situation, but it was unfortunate that you put yourself in that situation to begin with. If the Fox had quicker reactions, you were dead no matter what option you chose. Ask yourself, how did that happen? What should I have done differently before then to not put myself in that position?
0:54 - 0:59 - Great execution with that combo. The Fox DI'd in and you punished accordingly.
1:02 - Why are you at the edge of the stage at 72%? Yes the Fox has invincibility so he will catch you no matter where you are at the stage, but during his invincibility you need to be center stage and probably shielding. At 72%, your goal is to avoid his invincibility and get as much percent as you can afterwards until he wins an exchange.
1:12 - Good awareness.
1:20 - Again, if the Fox had better reactions and positioning, you would have been dead with a shine spike. You had plenty of recovery opportunities and you chose a high risk, low reward option. What was the more optimal recovery(ies)?
1:32 - You fortunate son of a gun.
1:35 - This is what you should of done @ 1:02, but I still would recommend being closer to center stage.
1:44 - Missed L-cancels and shine-grab opportunities. If you have 20XX, practice shine-grabs through shadowboxing.
1:55 - I view dash attacks like Marth's counter. If you use it too much, it's predicatble and avoidable, but use it only once and it can turn the tide. Unfortunately, dash attacking during invincibility was not your best option there plus it put you towards the edge of the stage and in return you got shined and are now in a horrible position.
2:04 - Good awareness again, the wall jump could maybe have been punished but it worked well.
2:08 - 2:12 - You're having a hard time getting out of this corner. He's attacking a lot and applying pressure mostly on your shield. How could you have gotten out of this pressure more easily?
2:28 - No need to run off the edge and try to shine him. You had enough time to turn around and either down smash or Bair reacting to whatever recovery option he chose.
2:52 - 2:58 - Your bad habit almost lost you the game. What's the best option during this sequence? (hint: starts with L, ends with "edge dashing")
3:11 - Double jump Dair may have sealed the game for you, unfortunately you chose to u-tilt which was fine, but hit stun + reaction time was not enough to follow up.
Hope this helps