>>7678915
for the bubbles, a general guide is to have one letters space between the text and bubble. if you look at the first panel the text goes pretty much all the way to the edge. treat bubbles and text like a physical object and give it room to breathe. you also have 5 sentences in that first one wich is a lot and could be split into 2-3.
next panel the bubble has some empty space above it (the top of the bubble and edge of the panel almost touch) and should just be expanded up to the edge. third panel the dialogue feels clunky. drop the um's, ah's and verbal filler, even if you're going for a realistic approach it's way too much.