Help!

Our real estate agent just called! She was able to reschedule our design team meeting for TOMORROW! I am so excited to finally get started on our house!
But now I desperately need advice! Ideas on bumping out garage walls, whether to enclose the lanai now or later, what to use for flooring, counters, what will "they" allow us to change in the house (doors, etc).
Help! All you people out there who have built a house from scratch here in TV!

OH< BTW, we are planning to build a designer Zinnia............
Connie