Back on topic, since you have previous experience from similar games, you may be patient enough for the following strategy?
It's about using the salary floor-free period. As a new team, you don't have to pay the salary floor in the first 16 weeks. It is very good, economically, to simply wait for that time, and only expand your arena. You are unlikely to promote anyway, since there are older, more advanced teams in your league.
How big are your TV contract and salary floor?