大家好-Hello

大家好，我想（给）（你们大家）（一点）关于我（的）给一点知识。我想介绍我自己一下
我的英文名字：Will
我是从美国南加州来的。
我非常喜欢学也（喜欢）教语言。
我的母语是英文。我也知道西班牙语和普通话。现在我自己（在）学意大利语。
谢谢阅读

大家好-Hello

大家好，我想关于我给一点知识。(This sounds like a straight translation from English. What were you trying to write?) 我想介绍一下我自己。一下
我的英文名字是Will。
我是从美国南加州来的。
我非常喜欢学也和教语言。
我的母语是英文。我也知道会说西班牙语和普通话。现在我自己在学意大利语。
谢谢阅读！

Hi Will! Nicely written. I hope my corrections are useful. Please note a few things:

1) Chinese has three ways to say "to know"： 知道 means to know information, 认识 means to know people, and 会 means to know a skill. Since I'm guessing you want to say you know how to speak Spanish and Mandarin, you must use 会.

2) 在 by itself has multiple uses, and one of them is to indicate that something is currently happening. Since you're saying that you're currently learning Italian, adding a 在 before the verb tells us it's ongoing.

Please feel free to ask if you have any more questions. 继续加油学习！