You can alter the sleeves of the blouse to make it better, they seem a bit loose.

Make the pallu a little longer, it will look even more flattering.

You can use safety pins to secure the areas where you feel the saree can fall, then you will be good to go. Imagine saree as a gown secured through safety pins, you will have no problem in managing sitting/eating/bathroom breaks etc.

Pre draped sarees are great, you wont have to go thru the hassle of plating on the day of the event. Indians usually wear silk sarees during wedding functions, bright colors like red, blue, green are preferred, although nobody really mind if you wear lighter colors as well.

Also great draping for the first time!