To access the game's Shop you must select the icon in the upper right corner of your screen, represented by a green cross, to the right of your coin balance.
When doing so, a new screen will be displayed with the different packages of coins and boosters that you can purchase, as well as the best offers.
Additionally, when leaving the Shop, you will have the possibility to view an ad, which will allow you to obtain 25 coins.
We invite you to visit the articles: How can I get coins? and What boosters can I find in the game?