(someone) got a haircut

Most people go to a professional stylist or barber when they want a haircut. You describe this service as:

I got my hair cut.

or

I got a haircut

Sometimes people will also say:

I cut my hair.

But that's a little confusing because it sounds like you did it yourself.

Aside from getting your hair cut, other services that you can "get" include:

• get your hair colored
• get an oil change (for your car)
• get a manicure (for your fingernails)
• get a massage

Why would you (do something)?

When someone asks "Why would you ___?" they usually don't want an answer. It's not really a question; it's a criticism. It means "You shouldn't ___!" For example:

Why would you invite someone out to lunch and then expect them to pay for it?

Why would you spend money on a new pair of headphones when you already have a pair sitting unopened at home?

go all the way (somewhere)

Use this phrase to talk about going somewhere far away or inconvenient:

I forgot my wallet, so I had to go all the way back home to get it.

a perfectly good (thing)

The phrase "perfectly good ___" means that something is good enough for a certain purpose.

We mostly use this phrase to criticize people who want to get something new instead of using something old. For example:

You want a new car? Why? You have a perfectly good vehicle already.

I buy him a perfectly good pair of jeans, and what does he do? He cuts off the bottom of the legs! Can you believe these kids these days?

Don't throw that away. It's still perfectly good.

right across the street

This phrase describes something that's directly in front of a building on the other side of the the street.

You can also use it to talk about somewhere that's very close by, but not literally right across the street.