How to delete a chosen element in array?
strInput = Console.ReadLine();
                    for (int i = 0; i < intAmount; i++)
                    {
                        if (strItems[i] == strInput)
                        {


                                strItems[i] = null;
                                for (int x = 0; x < intAmount-i; x++)
                                {
                                    i = i + 1;
                                    strItems[i - 1] = strItems[i];
                                }

                            intAmount = intAmount - 1;
                        }
                    }

var strItems = new string[] { "1", "2", "3", "4", "5" };

var list = new List<string>(strItems);
list.Remove("3");
strItems = list.ToArray();

int removeIndex = Array.IndexOf(strItems, "3");

if (removeIndex >= 0)
{
     // continue...
}

string strInput = Console.ReadLine();
string[] strItems = new string[] { "1", "2", "3", "4", "5" };

int removeIndex = Array.IndexOf(strItems, strInput);

if (removeIndex >= 0)
{
    // declare and define a new array one element shorter than the old array
    string[] newStrItems = new string[strItems.Length - 1];

    // loop from 0 to the length of the new array, with i being the position
    // in the new array, and j being the position in the old array
    for (int i = 0, j = 0; i < newStrItems.Length; i++, j++)
    {
        // if the index equals the one we want to remove, bump
        // j up by one to "skip" the value in the original array
        if (i == removeIndex)
        {
            j++;
        }

        // assign the good element from the original array to the
        // new array at the appropriate position
        newStrItems[i] = strItems[j];
    }

    // overwrite the old array with the new one
    strItems = newStrItems;
}

public bool MyDelete(int[] array, int value) // Easy to do for strings too.
{
    bool found = false;
    for (int i = 0; i < array.Length; ++i)
    {
        if (found)
        {
            array[i - 1] = array[i];
        }
        else if (array[i] == value)
        {
            found = true;
        }
    }
    return found;
}

public static T[] RemoveAt<T>(T[] array, int index) // hope there are not bugs, wrote by scratch.
{
    int count = array.Length - 1;
    T[] result = new T[count];

    if (index > 0)
        Array.Copy(array, 0, result, 0, index - 1);
    if (index < size)
        Array.Copy(array, index + 1, result, index, size - index);

    return result;
}

...
strItems = RemoveAt(strItems, index);