Panel one: "Yu!!" Panel two: "Uu (musical note)" Panel three: "Yu?" Panel four: "Yu!!!" (The yu is slurred, but I don't think it'd make a difference)
The girl thing is saying "hiya!" It literally says "eiya(small tsu, which indicates an exclamation point)", but hiya would be more recognizable to us English speakers.
Everything else is onomatopoeia. The last one's, for example, probably means 'thud'. The second panel's is the walking motions, maybe...? What Japan needs is a dictionary for this sort of stuff...