What does En la tiendo de ropa me gusta mucho la blusa mean in english?

Your example is missing a direct object at the beginning of the sentence. For example:

[Me/Te/Le/Nos/Os/Les] gusta la ropa en esta tienda.

It means, "[I/You (fam.)/You (form.)/We/You (pl. fam.)/They/] like the clothing in this store."