correct writing of ‘쩌어어’ is ‘저’ which means ’there’.
and the reason why she/he used ‘쩌어어’ in the sentence is to emphasize her/his expression like ‘there much more far away’ than just ‘there’.
if you use ㅉ instead of ㅈ, it makes word sounds stronger and in this case it sounds cuter too!
And about ‘쭈구’, the right separating from the sentence is ‘쭈구리’. which does not have exact translation word, but if I have to explain the nuance, it would be kind of ‘loser’, ‘pathetic’ not in strong way. you can imagine someone who seems like care about others too much and not confident. and we call him as a ‘쭈구리’!
I hope you could understand my explanation and would be useful to you!😂😂