I would like opinions on what I could have done better.
I learn from every cake and want to keep getting better
I had issues with lumpy looking cakes and have started using chocolate ganache as my crumb coat. It has really given my cakes a nice sharp edge, and much smoother overlay with both buttercream and fondant. Plus it does taste pretty good! It also helps keep the "bulge" from the filling, although I don't see that on your cake. :)
I might try making some practice fondant balls before finishing a cake to get the sizing right, they look a little big for the cake.
Also the middle layer seems shorter than the other two? Possibly, the ribbon is too big? If you can, figure out how much batter it takes to make a single layer for your cakes-ex. I make 3 tier cakes, so I know that it takes 3 cups of batter in a 9" round pan to create a 3/4" thick cake layer (after trimming). This way, my cakes are all the same 4" height. I will even use a ruler to make sure they come to the same height, and if need be, I will add more frosting to achieve a little extra height.
I spend a lot of time goofing and messing with my fondant to make sure it lays smooth on the cake. If you don't already have some, def get some of the fondant smoother paddles, they are very helpful!
The cap is beautifully smooth and has great sides, very straight.
A great cake, really good beginning! Keep practicing!!!!