Read the book "Blue Ocean Strategy" - helps you find latent customer needs, bigger competitors might not address

First you should make a study about the competitor's strength and weakness , it's about what customers like and needs .
Then how can you satisfy their needs through your product.

what problem does your app solve?
what is your differentiation? (price,localisation, technology etc)
what is your end goal/vision for the company?
(making a living vs a billion Dollar exit to a Tech Giant)

Let me know if you'd like to explore further!

Best,
Sinan

Get to know your users and find pain points not served by your competition. Once you figure out what to build, it becomes easier :)