I’m having trouble with the upper cut into the spin at the beginning are there any tutorials anywhere for an in depth look at it?
Where exactly is this? I assume you're talking about a boosted uppercut, but I can't think of any that are at the beginning of the run. Here's a few videos that might help you on that tho:
There’s this 20 min speed run on YouTube where a guy does it. I got it once but I’m having trouble doing it again
I’m thinking about this run
The one right at the beginning
Well, doing the flag proxy isn't recommended until you're at a very high level. But in general for boosteds, did you watch the videos I linked?