a waste of time

When something is "a waste of time", it means that you spend a lot of time doing it, but don't get any benefits from it in the end. This is a common phrase people use when they're talking about things that:

• they have to do but don't want to do (like waiting in a line)
• they want to do but don't think are useful (like playing video games or using some websites)

(someone) is such a (something)

The word "such" is similar to "so" except it's used with nouns instead of adjectives:

He's so handsome.

I used to be so lazy.

You're so goofy.

He's such a good-looking man.

I used to be such a procrastinator!

You're such a goofball!