In addition, you cannot reserve tickets on this shinkansen from outside of Japan. So it's a moot point.

There are Nozomi trains roughly every ten minutes. It is the JR-pass eligible Hikari train that runs every 30 minutes (note that the Hikari is slower simply because it stops a few times for 3-4 minutes at stations to let Nozomi trains pass, when it is running, it goes at the same speed).

Surprised no one has mentioned what is a usual refrain in this forum: if this is your first trip, why are you making Osaka instead of Kyoto your base in the south? Kyoto is far more interesting touristically.