Dynamic Columns and Rows Selecting all Loop

Hi,

I'm using a spreadsheet that is updated often, new rows and columns are added almost daily. I'm trying to use a loop to start as a column select all the data in the column apply the conditional formatting then move to the next column.

I know how to use a macro and apply the conditional formatting however, I'm struggling with trying to move along each column. Here is what I have so far:

Dim LastColumn As Long
Dim lngRows As Long
Dim rngC As Range

            LastColumn = Cells(1, Columns.Count).End(xlToLeft).Column

           lngRows = Cells(Rows.Count, 1).End(xlUp).Row
            Range("A1").Select
            Set rngC = Selection.CurrentRegion
            For j = 6 To LastColumn
           StartCel = Cells(2, j)
            LastCel = Cells(lngRows, j)
            
            Range(StartCel, LastCel).Select
            
            
            Next

I continue to get an error message saying I'm out of range when the program gets to "Range(StartCel,LastCel).Select".


In summary I want to just have a loop that goes through the spreadsheet and selects all the data in Column F then in column G,H etc.

I did not include my code about conditional formatting.

please help!

Thank you in advance for taking the time to help me!