The meaning is the same, refer to the first person.

But people don't use this word nowadays, this word is used in old times.

你好 Actually both words are used but in different context, specially when you are speaking about your company or your company members 我 or 我々 it´s common, so long story short, when you must use honorific terms it´s way better to use 我、for example:

公益法人として、我々はあらゆる年齢の子どもたちのために世界の最も良い場所をつくる有意義なメディアを作ることを信条としております。

As a Public Benefit Corporation (PBC), we  (the company) believe in creating meaningful media that makes the world a better place for kids of all ages. 

On the other hand if you are only speaking about yourself 私 comes way more natural.

Watashi

<em>Watashi </em>(私) is the standard, gender-free way to say “I” and is the first one learners are introduced to. If you don’t know which I-word to use, this is your best bet.

The only trap I know of is that in Japanese saying “<em>watashi mo</em>” (meaning: “me too”) can come off as very effeminate if you use it in an informal situation. Men should take care to say “<em>boku mo</em>” or use some other I-word instead.

Ware

Used more commonly in it’s “we” form (我々/<em>wareware</em>), <em>ware </em>(我) by itself and meaning just “I” is pretty uncommon, but not unheard of.

It’s also probably the the most difficult I-word in this post because depending on how you use it it can come out not only as “I” but either as “one’s self” (not necessarily the speaker),  or even “you” (although usage as “you” is very dated).

My impression of this word is it has a kind of wise, sage-like feeling to it. It’s almost always used in a short, declarative statement of some kind.