I’m a bit busty, but young. Should I aim for older roles because of that?

The larger bust line will age you. However, I would suggest aiming for the youngest role possible. That helps with longevity in the business. However, consider wearing a vest, jacket, loose top or something that camouflages the bust area. Just know that you are perfect just the way you are, but make the decision as to the type of roles/age group you would like to play.