On the stadium. Is better if u do seats frst one by one. It reduce the time that u stadium builds.
Always have good condition and morale in your players if u want better chances to win.
Power training is better recommend for fast trainer and gotta use alot of green boost.
Lv1-4 are not that challenging u get alot of inactive team. So save ur green pack to power train later
There are more experience player that might disagree with me but thats my opinion.