I have a userform with several textboxes, radio buttons, dropdowns, etc. When a user creates a new entry, the data is saved on the Data sheet, with one record occupying one row.
If you have one Button on your sheet to call the form, then just use something like this:
me.TextBox1.value = Cells(ActiveCell.Row, 2).Value 'ActiveCell.Row returns the row number of the current cell
So the only command the button has is UserForm1.Show
UserForm1.Show