Creating a Drop Down List where i can select multiple items, and they appear underneath.

Hello, I am trying to create some sort of stock Code, where every item has a number and a description.
I cant seem to get Vlookup to work for this take.
Col. A has the numbering col. B has the product description.

I want to be able to type for e.g. 1012 and the description for that Product number is selected e.g. Pop Rivet and its carried down.

Data Validation gives me an error that the list source must be a delimited, or a reference to a single row or column? I know its saying this because i have selected to Columns but if i do this with auto filter it kind of works where i can select a number and the description does show, but its not brought down and remembered, and it also doesnt show all the product numbers, Only about half i checked if there were any spaces or anything and i didnt see anything

I am new to Excel but i really need to get this done Asap, Any help or suggestions will be greatly appreciated.