I'm really struggling in my writing currently, not because of tones or misspelled pinyin, but because of the punctuation discrepancies. I don't understand why I keep getting marked wrong, and can't find any rules on where to put my commas or periods in sentences. Would anyone be able to tell me how many spaces go between words and punctuation, because at this point I'm at a loss! Here's a picture for example:

Thanks,
Hannah