Need project advice! Any experienced devs?

I am in the research phase of a new app that I will start writing and I am a bit confused on the tech stack. I want to scale this and make it a real business. I am an intermediate dev so a lot of the things I will be doing, I’ll learn on the way but I want to make a good choice on the tech stack cause that cant be changed later on.

Please let me know if I can pick your brain regarding the same. Thanks