It is grammatically correct but it would sound better if you used loudly or expressively. ex. The audience clapped their hands loudly.

'At' is very necessary because it shows that the school is where you are arriving. If you do not use it, your sentence will not make sense. The sentence would mean that you are performing the verb on the school, or arriving the school.

" Some people do shopping as often as they can. But you are especially crazy for shoping and you never save money." The first sentence is saying that many people shop (go buy things) whenever they can, whenever they have time, or as frequently as possible. The second sentence says that you are 'mentally strange', in other word wrong, to be shopping because you spend too much money instead of saving, conserving, it. I hope that answered your question. It was a bit hard to understand.

Are you interested in actually coming to the US and studying here? If so, it would be easy to take a class at the local community college. Depending on where you are staying, there may also be English courses offered. corrections: I want to study English in the United States, but I have no idea what the options are in training institutions (schools). Is there anyone who knows? I really need your help. If you know something about them or have ever studied at these English training institutions, it is pretty important for me to hear your suggestions.

I'M SO NERVOUS RIGHT NOW ! ! - 저는 지금 매우 긴장이됩니다 ! !

Why I'm nervous, first I'm (excited/expectant) to meet you 
and second I'm not good at English :)

But I tried talking to you, please welcome me.
Thank you,

왜 제가 긴장했냐면, 첫째 저는 당신들을 만날것에 기대가됩니다.
둘째 저는 영어를 잘 못합니다 ^^

하지만 전 당신들과 연결을 시도했고 , 제발 저를 환영해주세요 ~
감사합니다.

Learn English.

Why I'm learning English: Because I'm a Korean student. So I need English very, very much.