hello, I want to develop a game for Nintendo switch, and I want to ask how can I get a game I’ll create to the Nintendo store
This is nothing to do with Unity - you need to talk to nintendo. Unity merely supply the game engine, nintendo controls everything else, including your access to Unity switch support.
Note that you must buy a dev kit, and Nintendo isn’t letting just anyone into the program yet.
You need to sign up to be a Nintendo Developer, then send an email of interest to development support (found in the Developer Portal). They will give you instructions on what is needed and who to contact. You will need to submit a plan for your project and list your development experience history.