This cold day is chilly and already feeling just like winter. My clothing shop has had just one customer so far this afternoon. I had thought people would be buying more clothes now that it's colder. But still, let's be grateful for my one customer. She bought a whole bunch of clothes. Since "chilly" and "feeling" are both adjectives, they combine nicely: "it is chilly and feeling like winter". I said "let's be grateful" rather than "I am grateful" because it is good style to involve your reader.

It is a chilly cold day today and it is just like winter already. I have only got one customer in my clothes shop until now this afternoon. I thought they would go and buy clothes more when it gets colder. Anyway, I am still happy with just one customer. She bought a bunch of clothes. So….i made your description of the day adjectives.,,a cold and chilly day (they mean the same thing, so we probably don’t need both) I changed have just to have only…have just isn’t wrong at all, but it could mean that one customer only just came into the shop, so by using have only, it’s clear you’re referring to the number of customers, not the time they entered It gets colder, not it get. It is singular