There are several ways you can earn more Coins, listed below are things you may want to consider.
Upgrade your Structures
The best way to increase your income is to upgrade your buildings as doing so will enable them to produce more Coins and have larger storage capacity to collect them while you are away.
Build More Structures
Adding more structures to your park is not as expensive as upgrading your existing ones but it will generate fewer Coins than new rides or upgraded rides.
Change Cost of Park Entrance and Rides
A cheap price will lower your income and make customers happier. If you set the price for a ride too high it will decrease the amount of customers choosing it.
Acquire Coins Packs in the Shop
This is the quickest and easiest way to earn Coins but involves spending real money. Buying Coin packs allows you to build and upgrade buildings more quickly, and increase your income significantly.