At this point, put in miles, play around have fun. Go hard when you feel like going hard. Go easy when you feel like going easy.

You can play games if you want, sprint to the next sign, see if you can catch that rider up ahead.

But just put in miles. You'll improve rapidly. Once you've got a decent amount of miles in, you'll likely find that just riding hard every ride will cause your improvement to plateau. Then it will be time to get more structured in training if you want to continue to improve.