English speakers arrive with stress timing. Japanese gives each mora a similar beat, so ありがとう is a-ri-ga-to-o, not a-RI-ga-to. Drop the long vowel and you have said a different word.
ん is a full mora. Before p/b/m it leans toward m; before k/g it can be [ŋ]. The small っ is a hold, not a skip: ちょっと is cho-t-to. Tokyo pitch (atamadaka, nakadaka, odaka, heiban) is a melody, not English-style loudness.
On a Japanese lookup, turn on romanization in Settings and set caption gloss language to English. Mora chips and pitch notes sit under the clip so you can match what you hear to a count you can clap.