If you do not know how to write a simple loop that accesses each value in an Array, I believe you are at ground-zero in terms of programming in C#, let alone using ASP.NET.
There's nothing wrong
with being at "ground-zero;" we all start there :) And, the good thing is: if you start now, within a week or two you will never think you are "new" to C# again.
I've posted several times here on what I think are good resources (some free) for developing a basic competency in C# .NET: [^
I encourage you to focus your study on first mastering the essential elements of C#
.NET programming; there are certain things you need to learn which are common to almost all programming languages.
I would be concerned that if you do not start with a "foundation" in C# then moving on to the complex world of ASP.NET is going to be very difficult.
Creating "Higher-Level Objects:" in .NET C# those would be NameSpace, Class (static and non-static), Struct, Enum
"Scope" which means how to manage how the names of different objects you have created are evaluated at any given moment in the compilation/execution of your code
Flow-Of-Control: Loops: for, foreach, while, do. If/Else and Switch/Case structures.
Understanding .NET Types: Value Types, Reference Types; understanding Type conversion.
Variables (in .NET 'Fields) how to declare them, control their accessibility (scope).
Methods (static and non-static): passing parameters, returning results. passing by value, passing using 'out and 'ref.
Simple Math operators. operator precedence.
Boolean comparison. understanding use of 'null, string.IsEmpty, etc.
Basic Data Structures: Arrays, Generic Lists.