Go to Tools, Database Utilities, Switchboard Manager. Access will help you
create a Switchboard form to do what you wish.
It's not all that intuitive so you may have to give it a few tries to get
what you want. If you want to start over from scratch, delete both the
Switchboard form and Switchboard Items table. Speaking of the table, don't
change records in it manually unless you want to learn a lot the hard way
(which isn't always a bad thing).
Also you are limited to 8 buttons per page. Make sure that at least one
button is for going back to the Main Page.
When you are finished, go to Tools, Startup, and make Switchboard the
Display Form/Page. That way it opens first when starting up the database.