If you watch kpop star (the one with BoA, JYP, and YG) it has lots of good tips for singing and yadayada. 

Also when preparing for your audition you should learn to introduce yourself in Korean. One girl who was auditioning introduced herself in Korean and the judge looked up. That's really important when the judge looks up. It means they're interested in you, since judges for Global auditions barely looks up. So learn to introduce yourself in Korean.... GOOGLE it. You don't necessarily need to know how to introduce yourself in Korean, but it's recommended. At least know how to say hi (formally) in Korean. Koreans love when you greet them politely. 

PRACTICE MAKES PERFECT

When you're audition for dancing, I suggest you to practice free styling the most.

In order to improve free styling 

• Make sure to warm up or stretch BEFORE any practice. 
• Get a camera and video tape yourself (In the real audition they will film you and only if they are interested. You should film yourself to get used to having a camera watching you. The more comfortable you are, the easier it will be for your audition.)
• Have bunch of random dance songs that you have never heard before. In free styling you are dancing to a song you've never heard before and so you have to be quick. If you practice dancing to random songs, you will get the hang of reacting more quickly.
• Learn some dance choreography by some famous dancer or something, because learning dance moves and moving quickly to a song can help you freestyle better. It also can help you learn more dance moves (to use for free styling) since free styling is basically dancing to your own knowledge on dancing, but remember to add some groove and emotions into it (freestyle is not planned or choreographed ahead of time; make it as you go).

In order to improve singing

• Record yourself singing. You want to know how you sound like, so that you know what can be improved. Ex: to hold a note longer or be in the right pitch etc.
• Listen to the actual song repetitively so that you can get beats right or whatever
• Make sure to always warm up 
• If you're singing a song in another language, you should learn the right pronunciations first. Write the romanization if it helps you memorize it or pronounce it better
• When learning to memorize your lyrics, sing it over and over again. 

I'm just going to point it out that everyone will later develop their own practicing ways. This is just some ideas and ways to improve.

Always remember to enjoy it whether you're singing or dancing. If you seem to enjoy it then your audience will too.

Any questions? Or topics to cover? I will be glad to answer them because I know the feeling of wanting to reach your dreams. That's why I'll be glad to help you out. I wish I could've gotten help when I needed it but at least I did everything by myself. Anyways peace. BTW I will notify you guys if I updated any chapters, you know to make some things I went over more specific or more accurate. 

Also I will be busy during next month and so on, so I'm sorry if I can't get to you quickly.