For your list of matching items, if you want it to autocomplete, you're going to need to use a combobox + a macro.
First step is to create a list of groceries on your sheet or another worksheet. This list will be used to populate the "widget". You should make this list a Named Range to make your life a little easier later.
Then comes your "widget". You didn't specify which version of Excel you have, so you're going to need to find out how to add an ActiveX Combobox to your sheet.
Once you've done that, you'll need to open Visual Basic Editor - press Alt + F11 to do so.
In the left window, you'll see VBAProject([YourWorkbookName]) and folder under it called "Microsoft Excel Objects".
Expand that folder so that you see something called ThisWorkbook. Double click that and, in the right window, place the following code:
Private Sub Workbook_Open()
Sheets("Sheet1").ComboBox1.List = _
ComboBox1 with the actual name of your combobox (this is the default
for the first one inserted into a workbook)
Sheet1 with the name of your actual sheet
Range("A1:A56") with the location of your list of groceries. If you have it on another sheet, you can say Sheets("Sheet2").Range("A1:A56"). If you've given the range a name, such as "Groceries", you can replace it with just Range("Groceries") (named ranges are global).
What this does is tell Excel to populate that combobox with the list you tell it to when you open the workbook (you can check if it works by clicking the play button in VB Editor's toolbar). You'll need to have the option to enable macros.
I'm sure this will keep you busy for now :)