To do this properly in Excel, you'd have to write VBA to perform a bunch of tasks that any decent Access database can do without VBA, or at least much more efficiently with VBA.

Samples are usually available right on your PC if you did a complete install of Microsoft Access. Just choose to create a new database from the "Access database, wizards, and projects".

Do yourself a favor before you do anything else. Write yourself specifications. Think about what main pieces of information you'll be tracking, such as:
customers
orders
parts
inventory?
service reps/employees