1st:I am baking a 10 in. cake for the first time. Can I use only two flower nails and the baking strips to make sure it bakes evenly?

2nd: I am doing a buttercream cake with fondant decorations. (hills, railroad tracks, trees) How do I store the fondant until I am ready to apply it to the cake?

If you're making your decorations in advance, i save empty pizza boxes to store my fondant decorations until i need them. They keep the fondant safe and they stack nicely.

If you're just storing plain fondant in bulk, just wrap it in an airtight bag or put it in an airtight container until your ready to use it.

.........baking a 10 in. cake for the first time.....only two flower nails and the baking strips to make sure it bakes evenly? ..............

This is overkill
I have baked 1000s of 10" cake using none of that with great results. Using the baking strips will be *MORE* than enough.
If you need to keep the fondant decos soft you need to wrap or at least cover them with plastic wrap. If they can dry, then what the other poster said is great.

Baking srtips it is!

at 325 for about 60 minutes?

I'm just applying the fondant to the sides of the cake. So I'm not sure if it's supposed to be hard or soft.