hello

Soon refers to something that in coming in little time. Early is something that has come in less time than expected. Hope this brief explanation helps...

Quickly

There is a difference between soon and quickly. We use quickly to refer to the speed with which something is done. Soon means ‘before long’.

<ul style="margin-right: 0px; margin-bottom: 26px; margin-left: 40px; padding: 0px;"><li style="list-style-type: disc;">I got dressed quickly. (= I didn’t take a lot of time to get dressed.)</li></ul>

Early

Early means ‘near the beginning of a period of time we are talking about’. Early does not mean soon.
Compare:

<ul style="margin-right: 0px; margin-bottom: 26px; margin-left: 40px; padding: 0px;"><li style="list-style-type: disc;">Early this week, I had a strange experience. (NOT Soon this week, I had a strange experience.)</li><li style="list-style-type: disc;">He had an accident early this month.</li><li style="list-style-type: disc;">He will soon have an accident if he continues to drive like this. (NOT He will early have an accident…)</li><li style="list-style-type: disc;">I get up early in the morning. (NOT I get up soon in the morning.)</li></ul>

Early can mean ‘before the expected time’.

<ul style="margin-right: 0px; margin-bottom: 26px; margin-left: 40px; padding: 0px;"><li style="list-style-type: disc;">I arrived early.</li></ul>

Early can be used as an adjective.

<ul style="margin-right: 0px; margin-bottom: 26px; margin-left: 40px; padding: 0px;"><li style="list-style-type: disc;">We will be grateful for an early reply.</li></ul>

"Soon" is a general word meaning it's happening in a short amount of time from now. "Early" implies that something is occurring before you expected it to.

Let's say you ordered something online, and it's now 1:30 PM. You know that it is arriving at 2PM on your doorstep. You would say "it will arrive soon". It doesn't matter whether or not it was supposed to arrive at 1:00 or 3:00; soon merely implies that it will be here shortly in relation to the current time.

Early would be if, say, you expected the package at 2:00, but now at 1:30 you see the mailman driving up with your package. You didn't expect it at this time - it came before you expected it. "Oh, it arrived early!" you would say. 

Another example: you work shift starts at 9:00.

If you run out the door, late, at 9:15, but you know you'll be there in a few minutes, you would call your boss and apologize, saying "I'll be there soon!" You're not early for work - in fact, you're late! - but you know that you will be there in a short amount of time from now. If you arrived at work at 8:45, you would be early.

I hope this clears it up a little bit!