How many flower petals?

I would guess-timate anywhere from 500 - 700 petals depending on how lush you'd like it

Hey Selena!! This is such a beautiful ceremony space, will your wedding be similar?

This totally depends on how dense or sparse you want the petals to look. I would personally go for buying too many than too little as you will be able to use any leftover ones for decorating your dinner tables.

What color petals will you be using?

Not sure if this helps any but Ive been working on making my "aisle border" by gluing artificial petals to a base. Each strip in my pic above is 7.5 ft long and 11" at the widest. The petals are actually in layers, with 3 layers total.
I bought 3,000 petals total and this was around 1,100 petals that I used to make these two.