I"m attaching a simple example. I did not go to the trouble of laying out the address as you might want to do in an actual invoice (e.g., stringing City, State and ZIP into one line). But it illustrates the concept, and uses VLOOKUP to retrieve address lines from the database, on the second sheet.
But the database is created as a table, and there's a separate list of Company Names used for the generation of the drop down list. That separate list grows automatically, in alphabetical order, as you add company names and addresses to the database. You will need a current version of Excel for that automatic list to be generated. It uses the SORT function, which requires Excel 2021 or newer.
Let us know if you still have questions.
(By the way, an additional thing to consider doing for a really nicely formatted Invoice, is to use Word and MailMerge within Word, using the Excel database as the source of the information to populate the MailMerge document. That would give you more flexibility in layout of the invoice. But Excel by itself can also create an acceptable format; just wanted to make sure you were aware of both possibilities.)