Active Workbook issue

I am very new to writing/recording macros. I have code that works for sorting data in a worksheet. I recorded a macro, and then copied the code into my other macro in VBA. However, I want to be able to run the macro on any worksheet. When I recorded the macro, it identifies the specific active worksheet I was working in.

How do I change the following code so that I can use this macro on any worksheet that I open?

 Range(Selection, Selection.End(xlDown)).Select
    ActiveWorkbook.Worksheets("Region 2").Sort.SortFields.Clear
    ActiveWorkbook.Worksheets("Region 2").Sort.SortFields.Add Key:=Range( _
        "J3:J9999"), SortOn:=xlSortOnValues, Order:=xlAscending, DataOption:= _
        xlSortNormal
    With ActiveWorkbook.Worksheets("Region 2").Sort
        .SetRange Range("A3:M4783")
        .Header = xlGuess
        .MatchCase = False
        .Orientation = xlTopToBottom
        .SortMethod = xlPinYin
        .Apply
    End With

I also want to change the range I sort to capture however many lines of data the new worksheet may have. It may have 4000 rows, it may have 6000 rows. How do I change that?

Thank you!

Do you want to sort the entire used area of the worksheet?

This sorts the active worksheet:

Sub SortIt()
    Dim wks As Worksheet
    
    Set wks = ActiveSheet
    
    With wks.Sort
        .SortFields.Clear
        .SetRange wks.UsedRange
        .SortFields.Add Key:=wks.Range("J2"), _
                    SortOn:=xlSortOnValues, _
                    Order:=xlAscending, _
                    DataOption:=xlSortNormal
        .SortFields.Add Key:=wks.Range("H2"), _
                    SortOn:=xlSortOnValues, _
                    Order:=xlAscending, _
                    DataOption:=xlSortNormal
        .Header = xlYes
        .MatchCase = False
        .Orientation = xlTopToBottom
        .Apply
    End With
End Sub

In your example, the header was in row 2; not so?

Sub SortIt()
    Dim wks         As Worksheet

    Set wks = ActiveSheet

    With wks
        .UsedRange.Offset(1).Sort _
                Key1:=.Range("J2"), Order1:=xlAscending, _
                Key1:=.Range("H2"), Order2:=xlAscending, _
                Header:=xlYes, _
                MatchCase:=False, _
                Orientation:=xlTopToBottom
    End With
End Sub