Column number - copying and pasting from file to another file

Question

I have a little problem with my code. I want to copy my data from one file to my main file. When I check the code I meet with one problem. The code works fine until copied. In this line

Set cell1 = wsDest.Cells(1, Range("B1").End(xlToRight).Column + 1)

the cell is selected from the file from I am taking the data and not the folder I am pasting into.

I want my data to paste from these other files into the main file. I want to add them as columns, not rows.

Sub MoveCopyRowsColumns()

Dim mainWb As Workbook
Dim newWb As Workbook
Dim mainWs As Worksheet
Dim newWs As Worksheet
Dim strFolder As String

Set mainWb = Workbooks("Main_file.xlsm")
Set mainWs = mainWb.Worksheets("Worksheet1")

mainWs.Cells(1, Range("B1").End(xlToRight).Column + 1).Select
mainWs.Columns(ActiveCell.Column).EntireColumn.Delete

    strFolder = "C:\Users\User1\Desktop\Folder_with_files\"
    strFile = Dir(strFolder & "*.xls*")
    Do While strFile <> ""
        Set newWb = Workbooks.Open(strFolder & strFile)
        Set newWs = newWb.Sheets(1)
        
        strFile = Dir
        
        newWs.Cells(1, Range("B1").End(xlToRight).Column + 1).Select
        newWs.Columns(ActiveCell.Column).EntireColumn.Delete
        
        newWs.Range("B1", Range("B1").End(xlDown).End(xlToRight)).Copy _
        mainWs.Range("P1")
        
    Loop

End Sub