S.W.
I am a cake decorator and have done several cakes with fondant... the fondant decorations... flowers, bows, etc.. need to be made well in advance and dried till they are BONE DRY or they will sag and droop. Shape the bow around the handle of a spoon and place in a muffin cup to dry. You can place daisy flowers in muffin cups too to keep their 3D shape. Flatter flowers can lay flat on a cookie sheet and just dry for probably a week. Use a drier fondant when making flowers and decorations. You may want to try something smaller for a first cake because it sounds easy until you get into it and then it can get a bit tricky and time consuming, not to say you can't do it but you may run out of time and be disappointed with the results. I made a really cute girly birthday cake/cakes for my friends little girl, it was 3 cakes but in her case could be 2 and I mad them in a rounded bottom pan that looked like a hat when it was flipped over. Cut the top off the cake after it bakes and flip out onto a cake board, the cake board acts as the rim of the hat. I tinted the icing to pinks, different shades for each cake, and then used custom M&M's in brown and black, so that it looked like a polka dotted hat. tie a real ribbon around the bottom with a nice, REAL bow, and put fresh flowers around the base of the "hats" and they were elegant and VERY girly. She had a tea party and all the little girls wore hats... might be an idea to solve the bow problem, if you want more ideas, I have lots. I may even have a pic of that cake somewhere on my computer if you are interested, I will have to look, its been a while.
S..