How to find a specific cell and replace by a text - vba

Question

On an active range selection, how to find only the cells that contains "0" and "#N/A" - and replace it by text "NA" and change the font color to "red".
Here is the macro I am using to "convert formulas to absolute values " and "to find empty cells to put text "NA".
sub XConvertToValues()
Dim MyRange As Range
Dim MyCell As Range
Set MyRange = Selection
For Each MyCell In MyRange
If MyCell.HasFormula Then
MyCell.Formula = MyCell.Value
End If
If IsEmpty(MyCell.Value) = True Then
MyCell.Value = "NA"
End If
Next MyCell
End Sub

Answer 1

edited after OP's clarification about data format
use Replace() and AutoFilter() method of Range object
Sub XConvertToValues()
With Selection
.Value = .Value '<--| convert all formulas to their values
.Replace What:="#N/A", replacement:="NA", LookAt:=xlWhole
.Replace What:="0", replacement:="NA", LookAt:=xlWhole
If WorksheetFunction.CountIf(.Cells, "NA") > 0 Then
.AutoFilter field:=1, Criteria1:="NA"
.Resize(IIf(.Cells(1) = "NA", .Rows.count, .Rows.count - 1)).Offset(IIf(.Cells(1) = "NA", 0, 1)).SpecialCells(xlCellTypeVisible).Font.ColorIndex = 3
.Parent.AutoFilterMode = False
End If
End With
End Sub

Answer 2

i'm beginner too , this what can i make and maybe it will help you , you can just put number of cells you want to change or rewrite the code with FOR EACH
Dim i As Integer
On Error Resume Next
For i = 1 To 20
cells.Find(What:="0", MatchCase:=False_, SearchFormat:=False).Activate
ActiveCell.FormulaR1C1 = "NA"
With Selection.Font
.Color = -16776961
.TintAndShade = 0
End With
cells.Find(What:="#N/A", MatchCase:=False_, SearchFormat:=False).Activate
ActiveCell.FormulaR1C1 = "NA"
With Selection.Font
.Color = -16776961
.TintAndShade = 0
End With
Next i

Answer 3

edit
Now as you have provided more info, this can be done like:
Try this
Sub ConvertToValues()
Dim R As Long
k = Sheet1.Range("A1048576").End(xlUp).Row '-> total rows in column A
For R = 1 To k
If IsEmpty(Sheet1.Cells(R, 2)) = True Or Sheet1.Cells(R, 2) = "#NA" Or Sheet1.Cells(R, 2) = "0" Then
Sheet1.Cells(R, 2).Value = "NA"
Sheet1.Cells(R, 2).Font.Color = RGB(255, 0, 0)
End If
Next R
End Sub