Note: I'm aiming for anthe American English dialect.

It’s the name of something, therefore, use ‘the’ to denounce it.

As human beings, we can not control everything; whether it's people's actions, natural disasters and an so on.

There's a simple way to be proactive: firstly, take a pausebreath and focus on what you can control in your life or in that moment.

Or "what can I control in this situation?”.

".

ThusSo, the next time you're facing something you can't control just take a pause and remember "I can't control what happens to me but I can control how I react".

Thus is too formal for your writing style. Use so instead. Your writing is informal because you are addressing the audience using second person pronouns (“you”); it’s a more personal style, thus it is informal more than formal.

Thank you for correcting me. :)

typo

As human beings, we can not control everything; whether it's people's actions, natural disasters and an so on.

We don't use a semi-colon here because "whether it's people's actions, natural disasters and an so on" would be an incomplete sentence. When we use a semi-colon, both parts before and after it need to be complete sentences which can stand on their own.

That's why proactivity is so powerful;: instead of controlling what we can't, we can start controlling what we can: and that's ourselves.

Here, the second sentence explains why proactivity is powerful so we use a colon here. It's very, very rare to see two colons in a sentence.

The definition of proactivity is "tending to initiate change rather than reacting to events." iIn other words, it's the opposite of reactivity.

Just ask yourself, "wWhat's in my control?"

Or "wWhat can I control in this situation?

".

The question mark takes care of ending the sentence so we don't need a period after the quotation mark.

Thus, the next time you're facing something you can't control, just take a pause and remember, "I can't control what happens to me but I can control how I react"."

As human beings, we can not control everything; whether it's people's actions, natural disasters and an so on.