Hi, I'll be there doing the tri.

You've got 4 months to get ready; that's plenty of time to get used to your bike and get used to the distance.

For the duathlon I did in October I ditched the bike shoes and did the whole race in my running shoes, with PowerGrips on the bike pedals. I did this so as to greatly simplify the transitions and reduce their time to a minimum.

As you get used to the biking and running distances, you should also get used to the transition from one to the other. You should run, then bike and also bike then run, to get a feeling for what your legs will feel like going from one to the other. Also, practice the actual transition, changing from your running stuff to your biking stuff and also back. Try to keep it simple.