This is an unused 30 amp no power to it.

You can remove a breaker and use that spot for almost anything.

Your post is confusing. What are you looking to do exactly?

I am looking to add 2 outlets and a light in an upstairs bathroom and I don't want to overload any other circuits. So I am hoping that I could use the unused 30 amp spot to put in a couple of 15's and have one 15 for a spare. That way I'll have all NEW wiring going to the panel.

Sorry, I should say nothing is wired to the 30 amp but there is power to it.

Do you understand your question, because I do not. Do you have any training in electricity or electrical safety?

To begin with is this 30 amp breaker a single pole or double pole breaker? If it is a double breaker, then NO! If this is a two slot breaker, then the problem with using two separate 15 amp circuits would be that you create a "Multiwire Branch Circuit" This would then require that the Neutral be shared by both of the 15 amp circuits, If you do not do this correctly, then any thing you plug into the circuit will almost immediately fry.

Next, a breaker draws power from its connection point on the panelboard and in turn supplies the power to its circuit by the conductor connected to it.

So if you see a breaker, without a conductor does not mean the breaker is not hot. I've seen panelboeards where spare breakers were used instead of blanks to keep the front cover free from open holes.

Never understood that one either, use a $30 breaker instead of a $0,20 plastic cover.

I am looking to add 2 outlets and a light in an upstairs bathroom and I don't want to overload any other circuits. So I am hoping that I could use the unused 30 amp spot to put in a couple of 15's and have one 15 for a spare. That way I'll have all NEW wiring going to the panel.OK, so you just want to use the space provided by removing a double pole 30A breaker.

Absolutely fine. Consider that space like any other empty breaker space in the panel.

Yes you can, you could put in any size breaker or breakers you want. Just a note, make sure the outlet in the Bathroom is a GFCI.