It's going to be really tough in the first Round or two.
The trick is to build stable value, asap.
I suggest you fill your starting stable from the following horses:
Incentivise (I think he goes to the Turnbull over The Underwood)
Ayrton (will be near the top of the betting in the Epsom, if he makes the field!)
She's Ideel (will be close to fav in the Metro.)
Ingratiating, Four Moves Ahead, Jamaea, Heresy, Robodira, Hinged, Zouzarella, Najmaty, Mac'N'Cheese, Ranveer (pick 5 of these.)
If you fill your stable with 8 of the horses above, you will have horses that are close to favourite in the 4 Gp1's and one of the Gp2's.
It should leave you $200k to $400k left over, for making changes and improvements.