This is the truest better of a startup. One can expect to have a hand in every hour. This fast paced, multifaceted, and diverse true of work is ideal for the busy body who needs something to do.
What I wish was different
At a startup there is always lots to do. As such I got involved in everything. This is completely a fault of my own but sometimes time can feel stretched thin. It's more than easy to discuss this with management but was a strong leveling curve for me.
Advice
If you want a desk job, this is going to be fast paced for you. There never a boring day because every day it's different. If that diversity doesn't suit you, this will be an interesting experience for you.