Can I practice my meeting?
Yes. Your meeting becomes available to you immediately after you schedule it, so you can start it any time you'd like. Starting a meetingearly (whether by accident or on purpose so you could do a practice run through) does not affect your schedule or invitation in any way, so don't worry.
To practice your meeting, simply log in to your account and start your meeting just like you would if you were starting it for real. You can do this as many times as you'd like!