this (person/thing)

In the example above, the speaker uses "this" instead of "a". There's a small difference between the two. When you say "this ___" it sounds like you're talking about one specific thing. "A ___" is more general. 

You use "this ___" instead of "a" or "the" when you're introducing something specific that you're going to talk about. It's usually used at the beginning of a story or explanation. For example:

Amy and I were sitting there talking and this guy I know walked by.

I've had this song stuck in my head for two days!

Today I was talking with this girl at work who just got back from maternity leave.

In all of these examples, the speaker will continue by telling a story about that topic.

People only use "this ___" in this way in casual spoken English.

god-awful (something)

"God-awful" means really ugly, annoying, badly done, or unattractive. You use "god-awful" to talk about things that you don't like such as:

• bad music
• bad art
• bad writing
• a bad city

Although the word "god-awful" includes the word "god", most English speakers don't get offended by people using it.

techno music

To the average person who doesn't know a lot about it, "techno music" describes any kind of electronic music.

Among people who are interested in it, "techno music" has a more specific meaning.  

I've got (something)

"I've got ___" means "I have ___". For example:

I've got three left. What about you?

In American English, "I've got" sounds more casual than "I have".