(someone) is hot

When you call someone "hot", it means that they're attractive in a sexual way. You can describe a man or woman with a nice body as "hot".

This expression is casual. It's not rude, but there are certainly situations in which it's not appropriate to call someone "hot". For example, in an office environment it's usually not appropriate to call your coworkers "hot".

(a woman) is smokin' hot

Calling someone "hot" means that they're attractive. Calling a woman "smokin' hot" means that she is very, very attractive.

Being "smokin' hot" is a little different from being, for example "gorgeous". A "smokin' hot" woman is attractive in a sexual way. A "gorgeous" woman has a beautiful face and might be very well-dressed.

It is possible to describe a man as "smokin' hot", but much less common.

hang out with (someone)

"Hanging out with" someone means spending time together for fun. When you "hang out" with someone, you talk, eat, drink, laugh, watch movies, play games, etc.

This expression is slightly casual. You use it like this:

I hung out with Kim a few days ago.

Let's hang out sometime soon.

a chick

"Chick" is a slang term for a woman. You use it like this:

Chicks dig guys with money.

This means that women like men who have money.

This usage of the word "chick" is actually pretty old. It's the kind of thing that young men would say in the '50s. These days, "chick" seems a little old-fashioned, but it's still used sometimes.