I'd like to know your rankings and your reasoning. If it helps to give scores out of 6.0, by all means include them.
It's more of a floating scale than IJS is, since the actual scores don't contribute to the result. But in general junior scores could range anywhere from, say, mid 3s to mid 5s out of 6.
Oh, and if you think a specific skater is much better in technical ability than in presentation, or vice versa, feel free to give very different scores for the two marks, although historically judges rarely actually did so.