Your first priority must be to build a strong economy. Do not rush into war, do not waste your money, and do not spend skill points randomly. The early game is divided into two main priorities: skills and companies. At the beginning, the game is mainly about building your economy and your companies, so your main priority is to unlock and upgrade companies as fast as possible.
Every time you reach your current company limit — 2/2, then 3/3, then 4/4, then 5/5 — invest your next skill point in Companies to unlock a new slot. If you have enough money to build a new company, build it immediately and do not leave your money unused. When you cannot unlock a new company yet, follow this skill order: Production Level 1, Energy Level 1, Production Level 2, Energy Level 2, Production Level 3, Energy Level 3, Production Level 4, Production Level 5, Energy Level 4, Entrepreneurship Level 1, Entrepreneurship Level 2, Production Level 6, Energy Level 5, Production Level 7, and Energy Level 6.
Production determines the amount you produce in each work or entrepreneurship action. Energy is consumed when working for other companies, and each work session consumes 10 energy. Entrepreneurship is consumed when working in your own companies, and each session consumes 10 entrepreneurship. Workers determine how many employees you can hire, and you start with 4 free work slots. Do not hire workers at the beginning, because they may cost you more than they earn while your economy is still small. Finally, ignore war skills completely at the start. Your first goal is the economy, not combat.