a bit of a (something)

The phrase "a bit (adjective)" is similar in meaning to "a little":

It's a bit cold out.

The meaning of "a bit of a ___" is the same, but you use it before a noun instead of an adjective.

I know that it's a bit of a risk, but I really think we can pull it off.

a chill

A ‘chill’ is a light touch of cold in the air. It’s just cold enough to want a sweater. ‘Chill’ can be used in both formal and informal speech.

There's always a chill in the kitchen. I wonder if we should replace the windows in there.

in here

You can add “in” before “here” to emphasize that you are inside.

It’s hot in here!

there’s (something) (somewhere)

Use “there’s ___” to talk about something existing:

A: There's a problem.

B: Oh no. What's wrong?

Often we explain where something is by saying "there's (something) (somewhere):

There’s a weird smell in my car.

There’s a woman in my neighborhood who keeps over a dozen cats at her house.