go to options, theres a setting to skip cutscenes faster

There's a ton of stuff for learning the speedrun in the guides and resources section

https://docs.google.com/spreadsheets/d/14WJL-0vJHYOJzDzhrxfJQumMnMn5M8LD6qwwojogp0E/edit#gid=1486571340 temple will be a little worse tan everything else since this is before bubsdrop could be pause buffered but other than that this should be a pretty good reference

I’d recommend doing lots of training on individual sections and rooms to develop strategies if you want to get better. I’ve been playing Celeste for a little over a month now, but 20 hours on a practice file and looking up guide videos helped me get a 51:31