The first interesting thing happens when you have $5 of available funds. (Specifically, autoclippers become available to purchase.)
When precisely you hit that point depends on how well you are managing the price to balance ensuring that your unsold inventory is getting purchased reasonably quickly against getting a reasonable amount of money per unit sold, but it will probably be less than a minute.
I don't know. I'm at 16,285 and stuff is happening.
If you optimize your price and invest in auto clippers it shouldn't take too long to really get rolling.
If the available inventory is bouncing off of 0 your price is too low, if it's growing, it's too high, so you (as an AI) are learning about market clearing price right now. Later, you'll learn other things.