If the universe was made billions of years ago why is it only 2018.

Because time is a social construct. It was only created when civilization was created. Since there was no one to create time in the beginning of Earth we had to create it as far back as we could. So basically science as stuff created time to help people. Time wasn't a thing back then. It only became a thing when people became a thing. 

Hope this Helps!

I agree with the first person answer and basically it’s what I was going to say