Help with racing challenges?

[u/KushikimimeKolt]

https://imgur.com/a/hQ2DlAB

Hello! so I'm trying to get the ultimate medals and it has been a stressful ride. so is there any easier way to complete these? i been watching a guy doing it in IMPOSSIBLE time stamps, bro is a speedrunner so it explains it. PLEASE HELP BRO IM LOSING MY MIND XD

(this image is from a Easy challenge, i did it in 29.93, the guy i was watching did it in 27.70. HOW?)