每個人在變
在第一天開學，每個人在單獨（都是獨自一人），沒有朋友，對呢（吧）？好不容易終於找了朋友們。然後，一段時間後，每個人卻都變了，不是以前的自我（己）。朋友們和你再也不是以前的你們, 也不再那麼的相似一樣再也。你再次單獨（變成一個人）。直到找到別的人跟你有類似的喜好利益為你。但是我們天天在變。怎麽可以有永遠的好朋友們？
我最近逐漸認識了解到我前時候（以前）的朋友們經常（已經）跟我不一樣。我變了，我再次單獨一人。
如果看不懂：On the first day of school, everyone is alone. No one has friends, right? Eventually, finding friends. Suddenly, everyone changes, not their previous selves. [Your] friends and you aren't like each other anymore. Again by yourself. Until finding friends with similar interests as you, but everyday we are changing. How can [we] have friends that last forever?
A recently came to realize my friends from before and I now aren't alike. I changed, again, I'm alone.
You did a really good job! I can easily understand what you were trying to say.
Only few mistakes:
(1)呢 is used when you are really confused about something. If you already had a thoughts and want to ask people if they agree with you, it's better to use 吧（same as "right?"）
(2)
朋友們和你（your friend and you）再也不是(are no longer)以前的你們(the people you used to be)
也(and)不再(are no longer)那麼的(being so)相似(similar)
(3)
跟你(as you)有(has)類似(similar)的喜好(hobby) : who has similar hobby as you
(4)
認識 means "know （a person）"
For example: 我認識他（I KNOW him）
了解 means "understand and realize"
For example: 我了解了（I got it） 我了解到他已經變了（I realize that he has changed）
(5)
經常 means "often"
For example: 我上學經常遲到（I'm often late for calss） 遲到 verb. being late
已經 means "already"
For example: 我已經很累了（I am already very tired）
Purple parts are something native speakers like to use:
(1)單獨 does mean alone, but, in this situation, we like to use 獨自一人 which also means alone.
(2)we like to use 好不容易, when something is not easy to do but we eventually solve problem or achieve the goal.
(3)自我 is sort of formal. For eample: 自我實現（this is a term in psychology: self-actualization）
In daily live, we usually use “自己” For eample:他自己（himself）我自己（myself）
I know some of my English explainations may be weird. I apologize for that. Hope this is helpful for you. If you have any other questions, don't hesitate to ask me:)
每個人在變
在第一天開學，每個人是單獨，沒有朋友，對吧？終於找了朋友們。突然，每個人變了，不是他們以前的樣子。朋友們和你再也不一樣再也。你再次單獨。直到找到別的人和你有類似的興趣利益為.但是我們天天在變。怎麽可以有永遠好朋友們？
我最近逐漸認識到我前時候的朋友們以前的朋友經常跟我現在不一樣。我變了，我再次單獨。
如果看不懂：On the first day of school, everyone is alone. No one has friends, right? Eventually, finding friends. Suddenly, everyone changes, not their previous selves. [Your] friends and you aren't like each other anymore. Again by yourself. Until finding friends with similar interests as you, but everyday we are changing. How can [we] have friends that last forever?
A recently came to realize my friends from before and I now aren't alike. I changed, again, I'm alone.
每個人在變
(在)第一天開學開學的第一天，每個人在單獨都是孤獨的，沒有人有朋友，對呢吧？終於，找到了朋友們。然後突然，每個人都變了，不再是以前的自我。朋友們和你不一樣再也也不再一樣。再次單獨獨自一人。直到找到別的人有類似的利益為你與你有類似興趣的朋友。，但是，我們卻天天在變。怎麽可以如何擁有永遠的好朋友們？
我最近我逐漸(or use "開始")認識了解到我前時候的朋友們經常跟我不一樣與以前的朋友們不同了。我變了，我再一次，單獨我孤零一人("孤零" is the same as "獨自", "孤獨", "孤單") 。
如果看不懂：On the first day of school, everyone is alone. No one has friends, right? Eventually, finding friends. Suddenly, everyone changes, not their previous selves. [Your] friends and you aren't like each other anymore. Again by yourself. Until finding friends with similar interests as you, but everyday we are changing. How can [we] have friends that last forever?
A recently came to realize my friends from before and I now aren't alike. I changed, again, I'm alone.
每個人在變
在開學第一天，每個人（都）在单獨（自一人之中度过），沒有朋友，對吗呢？終於找了朋友們。然後，每個人變了，不是以前的自我。朋友們和你再也不一樣。再次（成为）單獨（一人）。直到找到与你有类似的利益（的）別的人。但是我們天天在變。怎麽可能有永遠的好朋友們呢我最近逐漸認識到我前時候的朋友們經常跟我不一樣（了）。我變了，我再次变成單獨（一人）。
如果看不懂：On the first day of school, everyone is alone. No one has friends, right? Eventually, finding friends. Suddenly, everyone changes, not their previous selves. [Your] friends and you aren't like each other anymore. Again by yourself. Until finding friends with similar interests as you, but everyday we are changing. How can [we] have friends that last forever?
A recently came to realize my friends from before and I now aren't alike. I changed, again, I'm alone.
每個人在變
在第一天開學，每個人都是單獨的，沒有朋友，對吧？終於找了朋友們。然後，每個人變了，不是以前的自我。朋友們和你再也不一樣。再次單獨。直到找到和你有相似興趣的朋友。但是我們天天在變。怎麽可以有永遠好朋友們？我最近逐漸意識到我以前時候的朋友們跟我不一樣。我變了，我再次單獨。
如果看不懂：On the first day of school, everyone is alone. No one has friends, right? Eventually, finding friends. Suddenly, everyone changes, not their previous selves. [Your] friends and you aren't like each other anymore. Again by yourself. Until finding friends with similar interests as you, but everyday we are changing. How can [we] have friends that last forever?
A recently came to realize my friends from before and I now aren't alike. I changed, again, I'm alone.
