Basic Information to starting the project

I have an startup project that I want to create that using Asp.Net core But many things are cause that be confused, there are:

1. What is ORM to use?
2. What architecture should I use? (like N-Tire,MVC or something like that)
3. What Common Design-Pattern should I use?
4. What Unit-Testing should I use?
5. What to use for the client?(like Angular,react,...)
6. What Software Engineering Methodology should I use?
7. Is selecting these things to improve the progress of the project?

And I have big Idea for this project, if I want to preventing data loss, what should I do? how do I go?

I would appreciate if anyone can help.