if I understand it well and you wish to initialize the TextBoxes in your UserForm with
values from your sheet, then you can add following procedure to the code module
of the UserForm...
UserForm_Initialize() is an event for UserForms and called every time you open
Private Sub UserForm_Initialize()
TextBox1.Value = ThisWorkbook.Worksheets("Main").Cells(1, 1).Value
TextBox2.Value = ThisWorkbook.Worksheets("Main").Cells(2, 1).Value
the UserForm. The TextBoxes are here initialized with the values from Cells A1 and A2.