When people go to real shops, the goods are visible. They can try clothes on and know what materials were used.
A personal pronoun at the beginning of a sentence refers back to the subject of the previous sentence, and in this case the subject of the previous sentence is ‘the goods’. ‘When people go to real shops’ is an adverb phrase. So obviously that doesn’t make sense: The goods can try clothes on!?
If you want to use ‘They’ as a substitute for ‘the goods’, that’s tricky but not impossible:
But that’s probably not what you wanted. You wanted ‘People’ as the subject of the second sentence, right? In that case you simply need to state the subject in the second sentence:
Now you have nice cohesion between the two sentences, with ‘people’ in both sentences. However, to make your writing more coherent you could be more specific about ‘people’:
And finally to avoid repetition you can do this:
So in fact you didn’t need to use pronoun substitution. Instead the two sentences are glued together (cohesive) thanks to the use of ‘people (who) go to real shops‘ in sentence 1 and ‘customers in real shops‘ in sentence 2.
You could probably also use a synonym for ‘real’ in sentence 2, but I can’t think of one. Can you? Comments below! 🙂