How to even do this please help.

Quote:

Write a program that takes a decimal value between 1 and 10 and displays its equivalent Roman numeral value.

This means that:

Input -> Result
1 -> I
2 -> II
3 -> III
4 -> IV
5 -> V
6 -> VI
7 -> VII
8 -> VIII
9 -> IX

Roman numbers aren't difficult, and this is a relatively simple problem that is given as homework to tens of thousands of students every year.
In this case it's trivial because you only have to deal with ten values:

 1    I
 2   II
 3  III
 4   IV
 5    V
 6   VI
 7  VII
 8 VIII
 9   IX
10    X

So, start by reading this: How to Write Code to Solve a Problem, A Beginner's Guide[^] and then think about what you have done in previous exercises.

I'm pretty sure you have read input from the user before, converted it to a number, done some processing on it, and printed the result - so there is the basis for your app:

public static void Main()
    {
    int value = Input.GetInteger("Enter value to convert to Roman Numerals (1 to 10 only)", 1, 10);
    string roman = ConvertToRoman(value);
    Console.WriteLine($"{value} is {roman} in Roman Numerals");
    }
private static string ConvertToRoman(int value)
    {
    ...
    }
...
public static class Input
    {
    public static int GetInteger(string prompt, int min, int max)
        {
        ...
        }
    }

Now all you have to do is "fill in the blanks" and write two very simple methods.
Hint: GetInteger will want a loop that reports problems until the user enters a valid number between the min and max, and you might want to look at the TryParse methods to convert the input to a number (Google will help you there).