Maybe means perhaps. When you are not sure about something.

Maybe I should bring my umbrella.

May be means "can" be.

You may be right. You should take your umbrella.

Yeah, you may be cool, but not as much as an unicorn.

To express uncertainty or a possibility: "There's something wrong with my computer. Maybe it's a virus." # adverb

"The train may be delayed." # Two separate words: modal and main/aux verb

You may be a bit confused.

"Would you like to goto the market?" 

"Maybe, I'm not sure"

You may be taller than me, but I am better looking.

Maybe I will help you, maybe I won't.

The water in the pond may be colder this time of year.

"Is it time for lunch yet?"

"Maybe."

It may be time for lunch.