我的哥哥会回来

我的哥哥要回来了(会 indicates a possiblity,but here I think you mean the fact that your brother is coming home)

明天我的哥哥会从大学回家(到家 means he's already home)。他的学年(shool year)已经完了，而且他没有别的地方可以去。我比较不喜欢这个情况，因为我的哥哥总是很吵。多数晚上我睡不着是因为他和朋友们总是做事(it's a little bit strange here by using 做事,probably you should mean something more specific,like party开派对)。每个晚上我都需要努力才能入睡。他一个叫Mclellan的朋友是最吵的(叫Mclellan is used as adj. here,so it's better to put it in front of 朋友)。他笑的时候，整个房间(or 房子。Here, 房间/房子 emphasises the space,but 家 is more emotional.)都可以听到。当他和朋友回来，我感觉压力很大，这太让我生气了。还有我的哥哥经常有很重的体味(umm.....臭 is a little bit strong,I think.You can use 大/重 to describe  thick smells)。

Try to use more commas or other punctuations.

Hopefully this is helpful. =)

我今天的学会

我今天的收获(学会是动词verb)

今天我考(考试是名词noun，一般说我有一门考试或者我考xx)高级听力口语。因为对我的选择题答案没有信心，所以我做错了。考试得分很低(“高低”一般形容分数like high or low for grades，“优差”形容结果like good or bad for results)。今天得到很多宝贵的收获(如标题，“学会”是learn是动词。一个“贵”字常用形容价格，expensive，“宝贵”强调价值value，像precious)。从今以后我一定对自己更有信心(相信是动词，信心是名词，正如believe和belief。“十分”虽然是表程度，但这里暗含比较的意思，所以用“更加”。)

Hopefully this is useful!=)

你好人人都 !

大家好！(we don't use 人人 while greeting,try 大家 next time.)

你好，我的名字是Matan。这是我第一次在这里用写东西(be aware of the order)。写中文对我来说还很难(普通话 is more like oral Chinese,but here I think you mean written characters)。我想在明年通过汉语水平考试。(be aware of the order again)

So firstly,the order may be the serious problem here.Right now it looks like you translated directly due to the order of you native language.Secondly,don't forget punctuations.Thirdly,choose the right word according to the situation.

Good luck with the exam,but there's more you can do for it.

Thanks,hope this is useful.