Yay! Another Warden cosplayer!
Anyways, I've been working on one myself as well. (Almost done, just need to make the top hat!!)
Okay, don't laugh, but I used this pattern for the top hat and the jacket.
Also, there are plenty of tutorials for how to use patterns scattered around the internet!
You could also use the pattern to make pants as well, if you wanted to. However, I was able to find pants in the right color as well as a yellow button down at the local goodwill. Thrift stores are a cosplayer's best friend~
For the shoes I just used my little brother's dress shoes (lol).
This is what I used for the weird belt thingy, and it also comes with a bow tie of the right color! Double deal!
I can't be much help on the glasses, but since it's close to Halloween there's bound to be glasses like that in at least one of the stores. I got mine from a local joke shop (was a lucky find).
For the fabric on the jacket I used corduroy(which is lovely), but suiting fabric or a cotton blend should work just fine!
As far as the sewing goes, I know how you feel. This was my first actual sewing project too! It's really good practice though, and I would advise you to try! You can always rip out the seams if you mess up. Haha!
As for the cane, I'm currently in the process of making one, and I'm using PVC for the stick part of it, and a wooden sphere of sorts for the head. Im basically rubbing glue over the whole thing and sanding, and then spray painting it to the right colors. I'm sure you could find a Willy Wonka Cane that looks like it though, and just paint over that.
Anyways, Good luck with your endeavors! Hope I helped!