VBA Runtime Error 1004 “Application-defined or Object-defined error” when setting Range in macro - vba

Question

I'm going to preface this by saying that I am very new to VBA and this is my first project with it however, I'm trying quite hard because otherwise it is manual copy paste ~200 times.
Unfortunately, for a first project it has been difficult.
EDITED FOR CLARITY (HOPEFULLY): The main idea is that I need to start at the beginning of a drop down list, copy the first string listed, then paste that string down the column. This changes the numerical data adjacent to the right. I then want to select this newly changed numerical data and copy and paste it to a different sheet in the same workbook in the first blank space in column F. I then want the code to iterate through the drop down list and do this for all 51 strings in the drop down. However it needs to paste offset by 3 columns for each iteration to copy the data to the correct column in the other sheet.
Here is my code thus far
Option Explicit
Sub PtComp()
'
' PtComp Macro
'
'
Dim List1 As String
Dim Range1 As Range
Dim Line1 As Range
Dim i As Integer
Dim Begin As Range
ActiveWorkbook.Sheets("Sample Data Summary").Activate
List1 = Selection
Set Range1 = Evaluate(ActiveSheet.Range(List1).Validation.Formula1)
For Each Line1 In Range1
Selection.Copy
ActiveSheet.Range(Selection, Selection.End(xlDown)).Select
ActiveSheet.Paste
ActiveCell.Offset(0, 1).Select
ActiveSheet.Range(Selection, Selection.End(xlDown)).Select
Application.CutCopyMode = False
ActiveSheet.Selection.Copy
ActiveWorkbook.Sheets("Pt Comparison").Activate
Begin = ActiveSheet.Range("F1").End(xlDown).Offset(-1, 0)
For i = 0 To 148 Step 3
Begin.Offset(0, i).Select
ActiveSheet.PasteSpecial Paste:=xlPasteValues
Next i
Next Line1
End Sub
It is highlighting this line
Set Range1 = Evaluate(ActiveSheet.Range(List1).Validation.Formula1)
Any help would be greatly appreciated. Sorry if my code is trash, like I said, first timer hoping to get better.
EDIT: Also, I looked back at older questions with the same error and thought that it was maybe because it wasn't clear what worksheet I was trying to define the range in, hence why my code is full of 'ActiveSheet' but still no luck.

Answer 1

Your code assumes List1 contains a valid range address, and thus that the active cell on that "Sample Data Summary" worksheet, contains a valid range address.
Apparently that isn't always the case. Search for more details on the On Error statement for ideas about how you could go about handling that situation.
You need to read up on How to avoid using Select in Excel VBA macros, and know that clipboard operations in a tight loop is pretty much the single slowest thing you can do in Excel-VBA.
Seems you want something like this:
Set Range1 = Evaluate(Selection.Validation.Formula1)
Your code blows up on Range(List1) because List1 does not contain a valid range address.